RFC 8984

JSCalendar: A JSON Representation of Calendar Data

📅 published July 2021, from ietf

RFC 8984: JSCalendar, but make it bestie-approved 💖

Okay so, first things first, the paperwork babe 📋✨ This one is RFC 8984, titled JSCalendar: A JSON Representation of Calendar Data 🎀. It came out in July 2021 and it's a Standards Track document 👑, which means it's the real deal, not just a suggestion. The authors are N. Jenkins and R. Stepanek, both from Fastmail 🦋. It's published in the IETF stream with ISSN 2070-1721 🌸.

It doesn't obsolete or update any earlier RFCs as far as this title block says, so it's a fresh start, no drama 💅.

Abstract ✨

Okay so this spec defines a data model and a JSON representation of calendar data 📅, made for storing it and swapping it around in calendaring and scheduling setups 🧚. It's giving "successor" energy: the goal is to be an alternative to, and over time replace, the super widely used iCalendar format 💜. It also wants to be unambiguous, extendable, and simple to process 🫶.

Now the tea ☕: jCal is also JSON, BUT it's a direct mapping from iCalendar. JSCalendar is different. It defines its own data model from scratch and expands semantics where it makes sense 🌈. Iconic behaviour, no notes 💅.

Status of This Memo 📜

This is an Internet Standards Track document 👑.

It's a product of the Internet Engineering Task Force (IETF) 🦋, and it represents the consensus of the IETF community 🫶. It went through public review and got approved for publication by the Internet Engineering Steering Group (IESG) ✨. If you want more info on Internet Standards, check out Section 2 of RFC 7841 🌸.

For the current status, any errata, and how to send feedback, head to https://www.rfc-editor.org/info/rfc8984 💖.

Copyright (c) 2021 IETF Trust and the persons identified as the document authors 🎀. All rights reserved ✨.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) as they stand on the publication date 📋. Please actually read these, bestie, because they spell out your rights and restrictions 🙈. Code Components pulled out of this document must include Simplified BSD License text, as described in Section 4.e of the Trust Legal Provisions, and they come without warranty as described in that license 💅.

Table of Contents 🗂️

1.  Introduction
  1.1.  Motivation and Relation to iCalendar and jCal
  1.2.  Notational Conventions
  1.3.  Type Signatures
  1.4.  Data Types
    1.4.1.  Id
    1.4.2.  Int
    1.4.3.  UnsignedInt
    1.4.4.  UTCDateTime
    1.4.5.  LocalDateTime
    1.4.6.  Duration
    1.4.7.  SignedDuration
    1.4.8.  TimeZoneId
    1.4.9.  PatchObject
    1.4.10. Relation
    1.4.11. Link
2.  JSCalendar Objects
  2.1.  Event
  2.2.  Task
  2.3.  Group
3.  Structure of JSCalendar Objects
  3.1.  Object Type
  3.2.  Normalization and Equivalence
  3.3.  Vendor-Specific Property Extensions, Values, and Types
4.  Common JSCalendar Properties
  4.1.  Metadata Properties
    4.1.1.  @type
    4.1.2.  uid
    4.1.3.  relatedTo
    4.1.4.  prodId
    4.1.5.  created
    4.1.6.  updated
    4.1.7.  sequence
    4.1.8.  method
  4.2.  What and Where Properties
    4.2.1.  title
    4.2.2.  description
    4.2.3.  descriptionContentType
    4.2.4.  showWithoutTime
    4.2.5.  locations
    4.2.6.  virtualLocations
    4.2.7.  links
    4.2.8.  locale
    4.2.9.  keywords
    4.2.10. categories
    4.2.11. color
  4.3.  Recurrence Properties
    4.3.1.  recurrenceId
    4.3.2.  recurrenceIdTimeZone
    4.3.3.  recurrenceRules
    4.3.4.  excludedRecurrenceRules
    4.3.5.  recurrenceOverrides
    4.3.6.  excluded
  4.4.  Sharing and Scheduling Properties
    4.4.1.  priority
    4.4.2.  freeBusyStatus
    4.4.3.  privacy
    4.4.4.  replyTo
    4.4.5.  sentBy
    4.4.6.  participants
    4.4.7.  requestStatus
  4.5.  Alerts Properties
    4.5.1.  useDefaultAlerts
    4.5.2.  alerts
  4.6.  Multilingual Properties
    4.6.1.  localizations
  4.7.  Time Zone Properties
    4.7.1.  timeZone
    4.7.2.  timeZones
5.  Type-Specific JSCalendar Properties
  5.1.  Event Properties
    5.1.1.  start
    5.1.2.  duration
    5.1.3.  status
  5.2.  Task Properties
    5.2.1.  due
    5.2.2.  start
    5.2.3.  estimatedDuration
    5.2.4.  percentComplete
    5.2.5.  progress
    5.2.6.  progressUpdated
  5.3.  Group Properties
    5.3.1.  entries
    5.3.2.  source
6.  Examples
  6.1.  Simple Event
  6.2.  Simple Task
  6.3.  Simple Group
  6.4.  All-Day Event
  6.5.  Task with a Due Date
  6.6.  Event with End Time Zone
  6.7.  Floating-Time Event (with Recurrence)
  6.8.  Event with Multiple Locations and Localization
  6.9.  Recurring Event with Overrides
  6.10. Recurring Event with Participants
7.  Security Considerations
  7.1.  Expanding Recurrences
  7.2.  JSON Parsing
  7.3.  URI Values
  7.4.  Spam
  7.5.  Duplication
  7.6.  Time Zones
8.  IANA Considerations
  8.1.  Media Type Registration
  8.2.  Creation of the "JSCalendar Properties" Registry
    8.2.1.  Preliminary Community Review
    8.2.2.  Submit Request to IANA
    8.2.3.  Designated Expert Review
    8.2.4.  Change Procedures
    8.2.5.  "JSCalendar Properties" Registry Template
    8.2.6.  Initial Contents for the "JSCalendar Properties"
            Registry
  8.3.  Creation of the "JSCalendar Types" Registry
    8.3.1.  "JSCalendar Types" Registry Template
    8.3.2.  Initial Contents for the "JSCalendar Types" Registry
  8.4.  Creation of the "JSCalendar Enum Values" Registry
    8.4.1.  "JSCalendar Enum Values" Registry Property Template
    8.4.2.  "JSCalendar Enum Values" Registry Value Template
    8.4.3.  Initial Contents for the "JSCalendar Enum Values"
            Registry
9.  References
  9.1.  Normative References
  9.2.  Informative References
Acknowledgments
Authors' Addresses

1. Introduction 🌸

Okay so this document defines a data model for calendar event and task objects 📅, plus groups of those objects, for electronic calendar apps and systems 🧚. It wants to be unambiguous, extendable, and simple to process 💖.

Here are the key design considerations, bestie 👑:

  • The attributes of a calendar entry have to be described as simple key-value pairs ✨. Simple events are simple to represent, and complex events can still be modelled accurately 💅.
  • Wherever possible, there should be only one way to express the desired semantics, which keeps things less complicated 🦋.
  • The data model should avoid ambiguities, because those lead to interoperability problems between implementations 🙈.
  • The data model should be generally compatible with the iCalendar data format [RFC5545] [RFC7986] and its extensions 🌈. But the spec adds new attributes where iCalendar is lacking expressivity, and drops seldom-used, obsolete, or redundant properties 💀. The point is that translating most common iCalendar files with no loss of semantics should be easy 🫶.
  • Extensions, like new properties and components, should not require updates to this document 🧚.

The representation is defined in the Internet JSON (I-JSON) format [RFC7493], which is a strict subset of the JSON data interchange format [RFC8259] 💜. Using JSON is mostly a pragmatic choice ✨. It's widely used, so JSCalendar is easier to adopt, and production-ready JSON implementations already exist, which wipes out a whole category of parser-related interoperability issues that iCalendar has often suffered from 😭🎀.

1.1. Motivation and Relation to iCalendar and jCal 🦋

Okay the iCalendar data format [RFC5545] is a widely deployed interchange format for calendaring and scheduling data 📅. It has served calendaring vendors for a long time, BUT it has some ambiguities and pitfalls that can't be fixed without backward-incompatible changes 💀.

Sources of implementation errors include the following 🙈:

  • iCalendar defines various formats for local times, UTC, and dates 🕐.
  • iCalendar requires custom time zone definitions inside a single calendar component 🌍.
  • iCalendar's definition of recurrence rules is ambiguous, and it has resulted in differing interpretations, even between experienced calendar developers 😭.
  • The iCalendar format itself causes interoperability issues because of misuse of CRLF-terminated strings, line continuations, and subtle differences among iCalendar parsers 💅.

In recent years, lots of new products and services have shown up that want to use a JSON representation of calendar data in their APIs 📱. The JSON format for iCalendar data, jCal [RFC7265], is a direct mapping between iCalendar and JSON 🧚. Trying to represent full iCalendar semantics, it inherits all the same pitfalls and uses a complicated JSON structure 😵‍💫.

So, since jCal was standardized, most implementations and service providers either kept using iCalendar or came up with their own proprietary JSON representations 🙃. Those are incompatible with each other and often suffer from common pitfalls, like storing event start times in UTC, which become incorrect if the time zone's rules change in the future ⏰. JSCalendar gives everyone JSON calendar data that avoids these known problems, plus a standard representation as an alternative to the proprietary formats 👑✨.

1.2. Notational Conventions 📝

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here 🫶.

The underlying format is JSON 💖. So the terms "object" and "array", plus the four primitive types (strings, numbers, booleans, and null), are to be interpreted as described in Section 1 of [RFC8259] 🌈.

Some examples in this document are "partial" JSON documents for illustration 🧚. In these examples, an ellipsis "..." stands in for a bit of the document that's been cut out for compactness ✂️.

1.3. Type Signatures 🔤

Type signatures are given for all JSON values in this document 💅. The following conventions are used:

  • "*": The type is undefined. The value could be any type, although permitted values may be constrained by the context of this value 🌀.
  • "String": This is the JSON string type 🎀.
  • "Number": This is the JSON number type 🔢.
  • "Boolean": This is the JSON boolean type ✅.
  • "A[B]": The keys are all of type "A" and the values are all of type "B" for a JSON object 🗝️.
  • "A[]": There is an array of values of type "A" 📚.
  • "A|B": The value is either of type "A" or of type "B" 🔀.

Other types may also be given. Their representations are defined elsewhere in this document 🦋.

1.4. Data Types 💎

In addition to the standard JSON data types, the following data types are used in this specification 🌸:

(Part 1 of 17 done bestie! 🎀 Part 2 picks up right after this, so stay tuned 💖)

1.4.1. Id ✨

Okay bestie, so "Id" as a data type means a "String" that's at least 1 and at most 255 octets in size 💅 It MUST only contain characters from the "URL and Filename Safe" base64url alphabet (see Section 5 of [RFC4648]), but excluding the pad character ("="). So the allowed characters are ASCII alphanumerics ("A-Za-z0-9"), hyphen ("-"), and underscore ("_") 🦋

JSCalendar uses a JSON map all over the place where the keys are Id and the values are all the same kind of object 🌸 That's basically an unordered set, with the bonus that every entry has a name (its map key). This makes patching way more concise, and when it applies, the objects can be referenced from other objects in the JSCalendar object. Iconic.

Unless a property says otherwise, there are no uniqueness constraints on an Id value. (Obviously you still can't have two entries with the same key in one JSON map 🙈) For example, two Event objects might use the same Ids in their links properties, or inside the same Event the same Id could show up in both participants and alerts. None of that implies any semantic connection between them. Not everything is connected, bestie.

1.4.2. Int

"Int" means an integer in the range -2^53+1 <= value <= 2^53-1. That's the safe range for integers stored in a floating-point double, and it's represented as a JSON Number 🔥

1.4.3. UnsignedInt

"UnsignedInt" means an integer in the range 0 <= value <= 2^53-1, represented as a JSON Number ✨

1.4.4. UTCDateTime

This is a string in the "date-time" [RFC3339] format, with some extra rules 💖 Any letters MUST be uppercase, and the time offset MUST be the character Z. Fractional seconds MUST NOT be included unless they're non-zero, and they MUST NOT have trailing zeros, so every date-time has exactly one representation. Very organized, I love that for us 🧚

For example, 2010-10-10T10:10:10.003Z is conformant. But 2010-10-10T10:10:10.000Z is invalid, and it gets correctly encoded as 2010-10-10T10:10:10Z 💅

1.4.5. LocalDateTime

This is a date-time string with no time zone or offset info 🌈 Otherwise it's in the same format as UTCDateTime, fractional seconds included. For example, 2006-01-02T15:04:05 and 2006-01-02T15:04:05.003 are both valid. The time zone comes from the "timeZone" property of the JSCalendar object (see Section 4.7.1). If no time zone is specified, the LocalDateTime is "floating". Floating date-times aren't tied to any specific time zone. Instead, they happen in each time zone at the given wall-clock time (as opposed to the same instant in time) ⏰

A time zone can have a period of discontinuity, like switching from standard time to daylight savings time. When you convert local date-times that land in that discontinuity to UTC, the offset before the transition MUST be used. Bestie, this part is so important 😭

Here's the drama. In the America/Los_Angeles time zone, the date-time 2020-11-01T01:30:00 happens twice: once before the daylight savings time (DST) transition with a UTC offset of -07:00, and again after the transition with an offset of -08:00. When converting to UTC, we use the offset before the transition (-07:00), so it becomes 2020-11-01T08:30:00Z 🍓

Similarly, in the Australia/Melbourne time zone, the date-time 2020-10-04T02:30:00 does not exist. The clocks jump forward one hour for DST on that day at 02:00. However, a value like that may still show up during calculations (see duration semantics in Section 1.4.6), or because the time zone rules changed (so it was valid when the event was first created). Again, it's interpreted as though the offset before the transition is in effect (+10:00). So when converted to UTC, we get 2020-10-03T16:30:00Z 🦋

1.4.6. Duration

Where Duration is given as a type, it means a length of time represented by a subset of the ISO 8601 duration format, specified by the following ABNF [RFC5234] 🎀

dur-secfrac = "." 1*DIGIT
dur-second  = 1*DIGIT [dur-secfrac] "S"
dur-minute  = 1*DIGIT "M" [dur-second]
dur-hour    = 1*DIGIT "H" [dur-minute]
dur-time    = "T" (dur-hour / dur-minute / dur-second)
dur-day     = 1*DIGIT "D"
dur-week    = 1*DIGIT "W"
dur-cal     = (dur-week [dur-day] / dur-day)

duration    = "P" (dur-cal [dur-time] / dur-time)

In addition, the duration MUST NOT include fractional second values unless the fraction is non-zero. Fractional second values MUST NOT have trailing zeros, so there's only a single representation for each duration 💅

A duration specifies an abstract number of weeks, days, hours, minutes, and/or seconds. A duration specified with weeks or days doesn't always equal an exact multiple of 24 hours 🌸 The number of hours, minutes, or seconds can vary if it overlaps a period of discontinuity in the event's time zone, like a switch from standard time to daylight savings time. And leap seconds MUST NOT be considered when adding or subtracting a duration to or from a LocalDateTime. Not the vibe, leap seconds, not here 🙅‍♀️

To add a duration to a LocalDateTime:

  1. Add any week or day components of the duration to the date. A week is always the same as seven days.
  2. If a time zone applies to the LocalDateTime, convert it to a UTCDateTime following the semantics in Section 1.4.5.
  3. Add any hour, minute, or second components of the duration (in absolute time).
  4. Convert the resulting UTCDateTime back to a LocalDateTime in the time zone that applies.

To subtract a duration from a LocalDateTime, the steps go in reverse:

  1. If a time zone applies to the LocalDateTime, convert it to UTC following the semantics in Section 1.4.5.
  2. Subtract any hour, minute, or second components of the duration (in absolute time).
  3. Convert the resulting UTCDateTime back to a LocalDateTime in the time zone that applies.
  4. Subtract any week or day components of the duration from the date.
  5. If the resulting time does not exist on the date due to a discontinuity in the time zone, use the semantics in Section 1.4.5 to convert to UTC and back to get a valid LocalDateTime.

These semantics match the iCalendar DURATION value type ([RFC5545], Section 3.3.6). Consistency across the calendar world, periodt 👑

1.4.7. SignedDuration

A SignedDuration is a length of time that can be positive or negative, and it's typically used to express the offset of a point in time relative to an associated time 🧚 It's represented as a Duration, optionally preceded by a sign character. It's specified by the following ABNF:

signed-duration = ["+" / "-"] duration

A negative sign indicates a point in time at or before the associated time. A positive sign, or no sign at all, indicates a time at or after the associated time 💜

1.4.8. TimeZoneId

Where "TimeZoneId" is given as a data type, it means a "String" that's either a time zone name in the IANA Time Zone Database [TZDB], or a custom time zone identifier defined in the "timeZones" property (see Section 4.7.2) 🌍

Where an IANA time zone is specified, the zone rules of the respective zone records apply. Custom time zones are interpreted as described in Section 4.7.2 🦋

1.4.9. PatchObject

A PatchObject is of type String[*] and it represents an unordered set of patches on a JSON object. Each key is a path in a subset of the JSON Pointer format [RFC6901]. The paths have an implicit leading "/", so each key gets prefixed with "/" before you apply the JSON Pointer evaluation algorithm. Math, but make it cute 🎀

A patch inside a PatchObject is only valid if all of the following conditions apply:

  1. The pointer MUST NOT reference inside an array. (Translation: you MUST NOT insert or delete from an array. The array MUST be replaced in its entirety instead 🙈)
  2. All parts prior to the last (the value after the final slash) MUST already exist on the object being patched.
  3. There MUST NOT be two patches in the PatchObject where the pointer of one is the prefix of the pointer of the other, like alerts/1/offset and alerts. Overlapping patches are a no, bestie.
  4. The value for the patch MUST be valid for the property being set (the correct type, and obeying any other applicable restrictions). Or, if it's null, the property MUST be optional.

The value tied to each pointer decides how that patch gets applied 💖

  • If null, remove the property from the patched object. If the key is not present in the parent, this a no-op.
  • If non-null, set the value given as the value for this property. This may be a replacement or an addition to the object being patched.

A PatchObject does not define its own "@type" property (see Section 4.1.1). An "@type" property in a patch MUST be handled like any other patched property value 🫶

Implementations MUST reject a PatchObject in its entirety if any of its patches are invalid. Implementations MUST NOT apply partial patches. No half-baked patches, ever 💀

The PatchObject format is used to significantly reduce file size and duplicated content when specifying variations on a common object, like recurring events or translating the data into multiple languages 🌈 It can also better preserve semantic intent if only the properties that should differ between two objects get patched. For example, if one person isn't going to a particular instance of a regularly scheduled event, then in iCalendar you'd have to duplicate the entire event in the override. In JSCalendar, it's just a small patch showing the difference. And since only that property is patched, if the location of the event changes, the occurrence will automatically still inherit it. Main character energy for the patch system ✨

1.4.10. Relation

A Relation object defines the relation to other objects, using a possibly empty set of relation types 🔥 The object that defines this relation is the linking object, and the other object is the linked object. A Relation object has the following properties:

  • @type: "String" (mandatory). This specifies the type of this object. This MUST be "Relation".
  • relation: "String[Boolean]" (optional, default: empty Object). This describes how the linked object is related to the linking object. The relation is defined as a set of relation types. If it's empty, the relationship between the two objects is unspecified 🌸

Keys in the set MUST be one of the following values: a value specified in the property definition where the Relation object is used, a value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 👑 The defined values are:

  • "first": The linked object is the first in a series the linking object is part of.
  • "next": The linked object is next in a series the linking object is part of.
  • "child": The linked object is a subpart of the linking object.
  • "parent": The linking object is a subpart of the linked object.

The value for each key in the map MUST be true 🦋

okay so a Link object represents an external resource attached to the object doing the linking 💖 it has the following properties:

  • @type: "String" (mandatory). This is the type of this object, bestie ✨ It MUST be "Link".
  • href: "String" (mandatory). This is a URI [RFC3986] where the resource can be fetched from 🫶 It MAY be a "data:" URL [RFC2397], but it is recommended that the file be hosted on a server so you don't stuff arbitrarily large data into JSCalendar object instances 🙈
  • cid: "String" (optional). This MUST be a valid "content-id" value according to the definition of Section 2 of [RFC2392]. The value MUST be unique within this Link object but has no meaning beyond that. It MAY be different from the link id for this Link object 🌸
  • contentType: "String" (optional). This is the media type [RFC6838] of the resource, if known 🎀
  • size: "UnsignedInt" (optional). This is the size, in octets, of the resource when fully decoded (i.e., the number of octets in the file the user would download), if known. Note that this is an informational estimate, and implementations must be prepared to handle the actual size being quite different when the resource is fetched. 🧚
  • rel: "String" (optional). This identifies the relation of the linked resource to the object. If set, the value MUST be a relation type from the IANA "Link Relations" registry [LINKRELS], as established in [RFC8288] 🦋
  • display: "String" (optional). This describes the intended purpose of a link to an image. If set, the "rel" property MUST be set to "icon". The value MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 💅
    • "badge": an image meant to be displayed alongside the title of the object
    • "graphic": a full image replacement for the object itself
    • "fullsize": an image that is used to enhance the object
    • "thumbnail": a smaller variant of "fullsize" to be used when space for the image is constrained
  • title: "String" (optional). This is a human-readable, plain-text description of the resource 🌈

2. JSCalendar Objects 📅

This section describes the calendar object types specified by JSCalendar.

2.1. Event 🎉

Media type: "application/jscalendar+json;type=event"

An Event represents a scheduled chunk of time on a calendar, typically a meeting, appointment, reminder, or anniversary. It's required to start at a certain point in time and typically has a non-zero duration. Multiple participants may partake in the event at multiple locations 💜

The @type (Section 4.1.1) property value MUST be "Event".

2.2. Task ✅

Media type: "application/jscalendar+json;type=task"

A Task is an action item, assignment, to-do item, or work item 💀 It may start and be due at certain points in time, take some estimated time to complete, and recur, none of which is required.

The @type (Section 4.1.1) property value MUST be "Task".

2.3. Group 🧺

Media type: "application/jscalendar+json;type=group"

A Group is a collection of Event (Section 2.1) and/or Task (Section 2.2) objects. Typically, objects are grouped by topic (e.g., by keywords) or calendar membership 🍓

The @type (Section 4.1.1) property value MUST be "Group".

3. Structure of JSCalendar Objects 🧱

A JSCalendar object is a JSON object [RFC8259], which MUST be valid I-JSON (a stricter subset of JSON) [RFC7493]. Property names and values are case sensitive, so capitalization matters, periodt 💅

The object has a collection of properties, as specified in the following sections. Properties are specified as being either mandatory or optional. Optional properties may have a default value if explicitly specified in the property definition ✨

3.1. Object Type 🏷️

JSCalendar objects MUST name their type in the @type property if not explicitly specified otherwise for the respective object type. A notable exception to this rule is the PatchObject (Section 1.4.9) 🙈

3.2. Normalization and Equivalence ⚖️

JSCalendar aims to provide unambiguous definitions for value types and properties but does not define a general normalization or equivalence method for JSCalendar objects and types. This is because the notion of equivalence might range from byte-level equivalence to semantic equivalence, depending on the respective use case. Normalization of JSCalendar objects is hindered for the following reasons:

  • Custom JSCalendar properties may contain arbitrary JSON values, including arrays. However, equivalence of arrays might or might not depend on the order of elements, depending on the respective property definition.
  • Several JSCalendar property values are defined as URIs and media types, but normalization of these types is inherently protocol and scheme specific, depending on the use case of the equivalence definition (see Section 6 of [RFC3986]).

Considering this, the definition of equivalence and normalization is left to client and server implementations and to be negotiated by a calendar exchange protocol or defined elsewhere 🫧

3.3. Vendor-Specific Property Extensions, Values, and Types 🎨

Vendors MAY add additional properties to the calendar object to support their custom features. To avoid conflict, the names of these properties MUST be prefixed by a domain name controlled by the vendor followed by a colon, e.g., "example.com:customprop". If the value is a new JSCalendar object, it either MUST include an "@type" property, or it MUST explicitly be specified to not require a type designator. The type name MUST be prefixed with a domain name controlled by the vendor 🦄

Some JSCalendar properties allow vendor-specific value extensions. Such vendor-specific values MUST be prefixed by a domain name controlled by the vendor followed by a colon, e.g., "example.com:customrel" 🌷

Vendors are strongly encouraged to register any new property values or extensions that are useful to other systems as well, rather than use a vendor-specific prefix. Main character energy, but make it a shared standard 👑

4. Common JSCalendar Properties 🗂️

This section describes the properties that are common to the various JSCalendar object types. Specific JSCalendar object types may only support a subset of these properties. The object type definitions in Section 5 describe the set of supported properties per type 💖

4.1. Metadata Properties 🪪

4.1.1. @type 🔖

Type: "String" (mandatory)

This specifies the type that this object represents. The allowed value differs by object type and is defined in Sections 2.1, 2.2, and 2.3 ✨

4.1.2. uid 🆔

Type: "String" (mandatory)

This is a globally unique identifier used to associate objects representing the same event, task, group, or other object across different systems, calendars, and views. For recurring events and tasks, the UID is associated with the base object and therefore is the same for all occurrences; the combination of the UID with a "recurrenceId" identifies a particular instance 🌸

The generator of the identifier MUST guarantee that the identifier is unique. [RFC4122] describes a range of established algorithms to generate universally unique identifiers (UUIDs). UUID version 4, described in Section 4.4 of [RFC4122], is RECOMMENDED 🫶

For compatibility with UIDs [RFC5545], implementations MUST be able to receive and persist values of at least 255 octets for this property, but they MUST NOT truncate values in the middle of a UTF-8 multi-octet sequence 🧩

4.1.3. relatedTo 🔗

Type: "String[Relation]" (optional)

This relates the object to other JSCalendar objects. It's represented as a map of the UIDs of the related objects to information about the relation 🕸️

If an object is split to make a "this and future" change to a recurrence, the original object MUST be truncated to end at the previous occurrence before this split, and a new object is created to represent all the occurrences after the split. A "next" relation MUST be set on the original object's relatedTo property for the UID of the new object. A "first" relation for the UID of the first object in the series MUST be set on the new object. Clients can then follow these UIDs to get the complete set of objects if the user wishes to modify them all at once 🦋

4.1.4. prodId 🏭

Type: "String" (optional)

This is the identifier for the product that last updated the JSCalendar object. This should be set whenever the data in the object is modified (i.e., whenever the updated property is set) 💅

The vendor of the implementation MUST ensure that this is a globally unique identifier, using some technique such as a Formal Public Identifier (FPI) value, as defined in [ISO.9070.1991] 🌍

This property SHOULD NOT be used to alter the interpretation of a JSCalendar object beyond the semantics specified in this document. For example, it is not to be used to further the understanding of nonstandard properties, a practice that is known to cause long-term interoperability problems 🙅‍♀️

4.1.5. created 🌱

Type: "UTCDateTime" (optional)

This is the date and time this object was initially created 🍼

4.1.6. updated 🕰️

Type: "UTCDateTime" (mandatory)

This is the date and time the data in this object was last modified (or its creation date/time if not modified since) 💜

4.1.7. sequence 🔢

Type: "UnsignedInt" (optional, default: 0)

Initially zero, this MUST be incremented by one every time a change is made to the object, except if the change only modifies the participants property (see Section 4.4.6) 📈

This is used as part of the iCalendar Transport-independent Interoperability Protocol (iTIP) [RFC5546] to know which version of the object a scheduling message relates to 📨

4.1.8. method 📮

Type: "String" (optional)

This is the iTIP [RFC5546] method, in lowercase. This MUST only be present if the JSCalendar object represents an iTIP scheduling message 💌

4.2. What and Where Properties 📍

4.2.1. title 🏷️

Type: "String" (optional, default: empty String)

This is a short summary of the object 🌟

4.2.2. description 📝

Type: "String" (optional, default: empty String)

This is a longer-form text description of the object. The content is formatted according to the descriptionContentType property 🎀

4.2.3. descriptionContentType 🖋️

Type: "String" (optional, default: "text/plain")

This describes the media type [RFC6838] of the contents of the description property. Media types MUST be subtypes of type "text" and SHOULD be "text/plain" or "text/html" [MEDIATYPES]. They MAY include parameters, and the charset parameter value MUST be "utf-8", if specified. Descriptions of type "text/html" MAY contain "cid" URLs [RFC2392] to reference links in the calendar object by use of the cid property of the Link object 🌈

4.2.4. showWithoutTime 🌞

Type: "Boolean" (optional, default: false)

This indicates that the time is not important to display to the user when rendering this calendar object. An example of this is an event that conceptually occurs all day or across multiple days, such as "New Year's Day" or "Italy Vacation". While the time component is important for free-busy calculations and checking for scheduling clashes, calendars may choose to omit displaying it and/or display the object separately to other objects to enhance the user's view of their schedule 🗓️

Such events are also commonly known as "all-day" events 🌼

4.2.5. locations 📍

Type: "Id[Location]" (optional)

Okay bestie, this is a map of location ids to Location objects 🗺️ It's basically a little address book for every place tied to your event, with each place getting its own id.

A Location object has the following properties. It MUST have at least one property other than the relativeTo property. Don't be the Location that's only got relativeTo and nothing else, that's a no-go 💅

@type: "String" (mandatory)

This tells you what kind of object it is. This MUST be "Location". Non-negotiable 🫶

name: "String" (optional)

The human-readable name of the location. Like "Blue Bottle Coffee" or "Room 4B" ☕

description: "String" (optional)

This is the human-readable, plain-text instructions for getting into this location 🚪 It can be an address, a set of directions, a door access code, etc. Basically whatever a person needs to actually find the place and get inside.

locationTypes: "String[Boolean]" (optional)

This is a set of one or more location types that describe this location. All types MUST be from the "Location Types Registry" [LOCATIONTYPES], as defined in [RFC4589]. The set is represented as a map, with the keys being the location types. The value for each key in the map MUST be true. So it's a little checklist, and every box you tick has to be checked as true ✅

relativeTo: "String" (optional)

This one is giving timing drama 🎭 It specifies the relation between this location and the time of the JSCalendar object. It's mainly there so travel events can say where you're departing from (at the start of the event) and where you're arriving (at the end). This is super important if those places are in different time zones, because a client may want to highlight that info for the user.

This MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3). Any value the client or server doesn't understand should be treated the same as if this property is omitted.

  • "start": The event/task described by this JSCalendar object occurs at this location at the time the event/task starts.
  • "end": The event/task described by this JSCalendar object occurs at this location at the time the event/task ends.

timeZone: "TimeZoneId" (optional)

This is a time zone for this location 🌍

coordinates: "String" (optional)

This is a "geo:" URI [RFC5870] for the location 📌

links: "Id[Link]" (optional)

This is a map of link ids to Link objects, representing external resources associated with this location, for example, a vCard or image 🖼️ If there are no links, this MUST be omitted (rather than specified as an empty set). So no empty links energy allowed 🙅‍♀️

4.2.6. virtualLocations 💻

Type: "Id[VirtualLocation]" (optional)

This is a map of virtual location ids to VirtualLocation objects, representing virtual locations such as video conferences or chat rooms that are associated with the object. The online spaces, basically 🎀

A VirtualLocation object has the following properties.

@type: "String" (mandatory)

This specifies the type of this object. This MUST be "VirtualLocation" 💜

name: "String" (optional, default: empty String)

This is the human-readable name of the virtual location. If you don't give one, it defaults to an empty String 🫥

description: "String" (optional)

These are human-readable plain-text instructions for accessing this virtual location. This may be a conference access code, etc. 🔑

uri: "String" (mandatory)

This is a URI [RFC3986] that represents how to connect to this virtual location. It's the actual link you click to join the call, so it's kind of a big deal 📞

This may be a telephone number (represented using the "tel:" scheme, e.g., "tel:+1-555-555-5555") for a teleconference, a web address for online chat, or any custom URI. Dial-in, web link, or something wild, all valid ✨

features: "String[Boolean]" (optional)

A set of features supported by this virtual location. The set is represented as a map, with the keys being the feature. The value for each key in the map MUST be true. Same checklist energy as before ✅

The feature MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3). Any value the client or server doesn't understand should be treated the same as if this feature is omitted.

  • audio: Audio conferencing 🎧
  • chat: Chat or instant messaging 💬
  • feed: Blog or atom feed 📰
  • moderator: Provides moderator-specific features 👑
  • phone: Phone conferencing ☎️
  • screen: Screen sharing 🖥️
  • video: Video conferencing 📹

Type: "Id[Link]" (optional)

This is a map of link ids to Link objects, representing external resources associated with the object. Think of it as the object's little bag of extra stuff 🛍️

Links with a rel of "enclosure" MUST be considered by the client to be attachments for download. So if it's an enclosure, the client has to treat it like a file you can grab 📎

Links with a rel of "describedby" MUST be considered by the client to be alternative representations of the description. Different ways of saying the same thing, iykyk 🌈

Links with a rel of "icon" MUST be considered by the client to be images that it may use when presenting the calendar data to a user. The "display" property may be set to indicate the purpose of this image. Cute little pictures for the UI 🥹

4.2.8. locale 🌐

Type: "String" (optional)

This is the language tag, as defined in [RFC5646], that best describes the locale used for the text in the calendar object, if known. Basically, what language is this in? 🗣️

4.2.9. keywords 🏷️

Type: "String[Boolean]" (optional)

This is a set of keywords or tags that relate to the object. The set is represented as a map, with the keys being the keywords. The value for each key in the map MUST be true. Hashtags, but make it structured ✨

4.2.10. categories 🗂️

Type: "String[Boolean]" (optional)

This is a set of categories that relate to the calendar object. The set is represented as a map, with the keys being the categories specified as URIs. The value for each key in the map MUST be true.

In contrast to keywords, categories are typically structured. For example, a vendor owning the domain "example.com" might define the categories "http://example.com/categories/sports/american-football" and "http://example.com/categories/music/r-b". Ngl, the URIs make this feel very organised and very main character 👑

4.2.11. color 🎨

Type: "String" (optional)

This is a color clients MAY use when displaying this calendar object. The value is a color name taken from the set of names defined in Section 4.3 of CSS Color Module Level 3 [COLORS] or an RGB value in hexadecimal notation, as defined in Section 4.2.1 of CSS Color Module Level 3. Pick a shade, bestie, the client might show it off 💅🌸

4.3. Recurrence Properties 🔁

Some events and tasks occur at regular or irregular intervals. Rather than having to copy the data for every occurrence, there can be a base event with rules to generate recurrences and/or overrides that add extra dates or exceptions to the rules. So you write it once and let the rules do the rest, lazy girl genius 🧠✨

The recurrence set is the complete set of instances for an object. It is generated by considering the following properties in order, all of which are optional:

  1. The "recurrenceRules" property (Section 4.3.3) generates a set of extra date-times on which the object occurs.
  2. The "excludedRecurrenceRules" property (Section 4.3.4) generates a set of date-times that are to be removed from the previously generated set of date-times on which the object occurs.
  3. The "recurrenceOverrides" property (Section 4.3.5) defines date-times that are added or excluded to form the final set. (This property may also contain changes to the object to apply to particular instances.)

4.3.1. recurrenceId 🆔

Type: "LocalDateTime" (optional)

If present, this JSCalendar object represents one occurrence of a recurring JSCalendar object. If present, the "recurrenceRules" and "recurrenceOverrides" properties MUST NOT be present. So one instance can't also be the whole rule-maker, no double dipping 🙅‍♀️

The value is a date-time either produced by the "recurrenceRules" of the base event or added as a key to the "recurrenceOverrides" property of the base event. It's the exact moment this one occurrence lands on 📅

4.3.2. recurrenceIdTimeZone 🌏

Type: "TimeZoneId|null" (optional, default: null)

Identifies the time zone of the main JSCalendar object, of which this JSCalendar object is a recurrence instance. This property MUST be set if the "recurrenceId" property is set. It MUST NOT be set if the "recurrenceId" property is not set. So they're a package deal: recurrenceId shows up, this shows up too, and if one's missing, the other sits this one out 🫶

4.3.3. recurrenceRules ✨

  • recurrenceRules is the bestie of repeating stuff 🔁 Type: "RecurrenceRule[]" (optional)

Okay so this property defines a whole set of recurrence rules (repeating patterns) for recurring calendar objects 🦋

An Event recurs by applying the recurrence rules to its "start" date-time. Simple and iconic 💅

A Task is a little different. It recurs by applying the rules to its "start" date-time if that's defined. If not, it recurs by its "due" date-time, if that's defined. If the task has neither a "start" nor a "due" date-time, it MUST NOT define a "recurrenceRules" property 🙈

If there are multiple recurrence rules, each one gets applied, and then the union of the results is used, ignoring any duplicates. Union just means everyone shows up once, no double-dipping 🌸

A RecurrenceRule object is basically the JSON object version of a RECUR value type from iCalendar [RFC5545] [RFC7529], and it has the same semantics. It has the following properties:

  • @type: "String" (mandatory)
    • This specifies the type of this object. This MUST be "RecurrenceRule".
  • frequency: "String" (mandatory)
    • This is the time span covered by each iteration of this recurrence rule (see Section 4.3.3.1 for full semantics). This MUST be one of the following values:
      • "yearly"
      • "monthly"
      • "weekly"
      • "daily"
      • "hourly"
      • "minutely"
      • "secondly"
    • This is the FREQ part from iCalendar, converted to lowercase.
  • interval: "UnsignedInt" (optional, default: 1)
    • This is the interval of iteration periods at which the recurrence repeats. If included, it MUST be an integer >= 1.
    • This is the INTERVAL part from iCalendar.
  • rscale: "String" (optional, default: "gregorian")
    • This is the calendar system in which this recurrence rule operates, in lowercase. This MUST be either a CLDR-registered calendar system name [CLDR] or a vendor-specific value (see Section 3.3).
    • This is the RSCALE part from iCalendar RSCALE [RFC7529], converted to lowercase.
  • skip: "String" (optional, default: "omit")
    • This is the behavior to use when the expansion of the recurrence produces invalid dates. This property only has an effect if the frequency is "yearly" or "monthly". It MUST be one of the following values:
      • "omit"
      • "backward"
      • "forward"
    • This is the SKIP part from iCalendar RSCALE [RFC7529], converted to lowercase.
  • firstDayOfWeek: "String" (optional, default: "mo")
    • This is the day on which the week is considered to start, represented as a lowercase, abbreviated, and two-letter English day of the week. If included, it MUST be one of the following values:
      • "mo"
      • "tu"
      • "we"
      • "th"
      • "fr"
      • "sa"
      • "su"
    • This is the WKST part from iCalendar.
  • byDay: "NDay[]" (optional)
    • These are days of the week on which to repeat. An "NDay" object has the following properties:
      • @type: "String" (mandatory)
        • This specifies the type of this object. This MUST be "NDay".
      • day: "String" (mandatory)
        • This is a day of the week on which to repeat; the allowed values are the same as for the "firstDayOfWeek" recurrenceRule property.
        • This is the day of the week of the BYDAY part in iCalendar, converted to lowercase.
      • nthOfPeriod: "Int" (optional)
        • If present, rather than representing every occurrence of the weekday defined in the "day" property, it represents only a specific instance within the recurrence period. The value can be positive or negative but MUST NOT be zero. A negative integer means the nth-last occurrence within that period (i.e., -1 is the last occurrence, -2 the one before that, etc.).
        • This is the ordinal part of the BYDAY value in iCalendar (e.g., 1 or -3).
  • byMonthDay: "Int[]" (optional)
    • These are the days of the month on which to repeat. Valid values are between 1 and the maximum number of days any month may have in the calendar given by the "rscale" property and the negative values of these numbers. For example, in the Gregorian calendar, valid values are 1 to 31 and -31 to -1. Negative values offset from the end of the month. The array MUST have at least one entry if included.
    • This is the BYMONTHDAY part in iCalendar.
  • byMonth: "String[]" (optional)
    • These are the months in which to repeat. Each entry is a string representation of a number, starting from "1" for the first month in the calendar (e.g., "1" means January with the Gregorian calendar), with an optional "L" suffix (see [RFC7529]) for leap months (this MUST be uppercase, e.g., "3L"). The array MUST have at least one entry if included.
    • This is the BYMONTH part from iCalendar.
  • byYearDay: "Int[]" (optional)
    • These are the days of the year on which to repeat. Valid values are between 1 and the maximum number of days any year may have in the calendar given by the "rscale" property and the negative values of these numbers. For example, in the Gregorian calendar, valid values are 1 to 366 and -366 to -1. Negative values offset from the end of the year. The array MUST have at least one entry if included.
    • This is the BYYEARDAY part from iCalendar.
  • byWeekNo: "Int[]" (optional)
    • These are the weeks of the year in which to repeat. Valid values are between 1 and the maximum number of weeks any year may have in the calendar given by the "rscale" property and the negative values of these numbers. For example, in the Gregorian calendar, valid values are 1 to 53 and -53 to -1. The array MUST have at least one entry if included.
    • This is the BYWEEKNO part from iCalendar.
  • byHour: "UnsignedInt[]" (optional)
    • These are the hours of the day in which to repeat. Valid values are 0 to 23. The array MUST have at least one entry if included. This is the BYHOUR part from iCalendar.
  • byMinute: "UnsignedInt[]" (optional)
    • These are the minutes of the hour in which to repeat. Valid values are 0 to 59. The array MUST have at least one entry if included.
    • This is the BYMINUTE part from iCalendar.
  • bySecond: "UnsignedInt[]" (optional)
    • These are the seconds of the minute in which to repeat. Valid values are 0 to 60. The array MUST have at least one entry if included.
    • This is the BYSECOND part from iCalendar.
  • bySetPosition: "Int[]" (optional)
    • These are the occurrences within the recurrence interval to include in the final results. Negative values offset from the end of the list of occurrences. The array MUST have at least one entry if included. This is the BYSETPOS part from iCalendar.
  • count: "UnsignedInt" (optional)
    • These are the number of occurrences at which to range-bound the recurrence. This MUST NOT be included if an "until" property is specified.
    • This is the COUNT part from iCalendar.
  • until: "LocalDateTime" (optional)
    • These are the date-time at which to finish recurring. The last occurrence is on or before this date-time. This MUST NOT be included if a "count" property is specified. Note that if not specified otherwise for a specific JSCalendar object, this date is to be interpreted in the time zone specified in the JSCalendar object's "timeZone" property.
    • This is the UNTIL part from iCalendar.

4.3.3.1. Interpreting Recurrence Rules ✨

okay so a recurrence rule is basically the thing that tells you which date-times a recurring calendar object lands on 📅 here's the whole semantic breakdown, bestie 💅 quick heads up: anywhere you see "year", "month", or "day of month", that's all inside the calendar system set by the rscale property 🌸, which defaults to "gregorian" if it's left out.

  1. Generate the candidates 🎀 A set of candidates gets made. It's every second inside a period that depends on the frequency value:
    • "yearly": every second from midnight on the first day of a year (inclusive) to midnight on the first day of the following year (exclusive).
      • If skip is not "omit", the calendar system has leap months, and there is a byMonth property, generate candidates for the leap months, even if they don't occur in this year.
      • If skip is not "omit" and there is a byMonthDay property, presume each month has the maximum number of days any month may have in this calendar system when generating candidates, even if it's more than this month actually has.
    • "monthly": every second from midnight on the first day of a month (inclusive) to midnight on the first of the following month (exclusive).
      • If skip is not "omit" and there is a byMonthDay property, presume the month has the maximum number of days any month may have in this calendar system when generating candidates, even if it's more than this month actually has.
    • "weekly": every second from midnight (inclusive) on the first day of the week (as defined by the firstDayOfWeek property or Monday if omitted) to midnight seven days later (exclusive).
    • "daily": every second from midnight at the start of the day (inclusive) to midnight at the end of the day (exclusive).
    • "hourly": every second from the beginning of the hour (inclusive) to the beginning of the next hour (exclusive).
    • "minutely": every second from the beginning of the minute (inclusive) to the beginning of the next minute (exclusive).
    • "secondly": only the second itself.
  2. Filter with the byX properties 🔍 Each date-time candidate gets compared against all of the byX properties of the rule except bySetPosition. If any property in the rule doesn't match the date-time, that date-time is eliminated 💀. Each byX property is an array, and the date-time matches the property if it matches any of the values in the array. Here's what each one does:
    • byMonth: The date-time is in the given month.
    • byWeekNo: The date-time is in the nth week of the year. Negative numbers mean the nth last week of the year. This follows the week numbering defined in ISO.8601.2004, where a week is a seven-day period starting on the firstDayOfWeek property value (or Monday if omitted). Week number one of the calendar year is the first week that contains at least four days in that calendar year.
      • If the date-time is not valid (this may happen when generating candidates with a skip property in effect), it is always eliminated by this property.
    • byYearDay: The date-time is on the nth day of the year. Negative numbers mean the nth last day of the year.
      • If the date-time is not valid (this may happen when generating candidates with a skip property in effect), it is always eliminated by this property.
    • byMonthDay: The date-time is on the given day of the month. Negative numbers mean the nth last day of the month.
    • byDay: The date-time is on the given day of the week. If the day is prefixed by a number, it's the nth occurrence of that day of the week within the month (if frequency is monthly) or year (if frequency is yearly). Negative numbers mean the nth last occurrence within that period.
    • byHour: The date-time has the given hour value.
    • byMinute: The date-time has the given minute value.
    • bySecond: The date-time has the given second value.

If a skip property is defined and is not "omit", there may be candidates that don't correspond to valid dates (e.g., February 31st in the Gregorian calendar). In this case, the properties MUST be considered in the order above, and:

  1. After applying the byMonth filter, if the candidate's month is invalid for the given year, increment it (if skip is "forward") or decrement it (if skip is "backward") until a valid month is found, incrementing or decrementing the year as well if passing through the beginning or end of the year. This only applies to calendar systems with leap months.
  2. After applying the byMonthDay filter, if the day of the month is invalid for the given month and year, change the date to the first day of the next month (if skip is "forward") or the last day of the current month (if skip is "backward").
  3. If any valid date produced after applying the skip is already a candidate, eliminate the duplicate. (For example, after adjusting, February 30th and February 31st would both become the same "real" date, so one is eliminated as a duplicate.)
  1. Apply bySetPosition 🎯 If a bySetPosition property is included, it now gets applied to the ordered list of remaining dates. This property specifies the indexes of date-times to keep, and all others should be eliminated. Negative numbers are indexed from the end of the list, with -1 being the last item, -2 the second from last, and so on.
  2. Drop the early birds 🐣 Any date-times before the start date of the event are eliminated (see below for why this might be needed).
  3. No repeats, bestie 🙅 If a skip property is included and is not "omit", eliminate any date-times that have already been produced by previous iterations of the algorithm. (This is not possible if skip is "omit".)
  4. Loop it 🔁 If further dates are required (we have not reached the until date or count limit), skip the next (interval - 1) sets of candidates, then continue from step 1.

When determining the set of occurrence dates for an event or task, the following extra rules must be applied:

  1. The initial date-time the rule is applied to (the "start" date-time for events or the "start" or "due" date-time for tasks) is always the first occurrence in the expansion, and it is counted if the recurrence is limited by a count property, even if it would normally not match the rule. ✨
  2. The first set of candidates to consider is the one that would contain the initial date-time. This means the first set may include candidates before the initial date-time, and those candidates are eliminated from the results in step 4 of the list above. 🧐
  3. The following properties MUST be implicitly added to the rule under the given conditions:
    • If frequency is not "secondly" and there is no bySecond property, add a bySecond property with the sole value being the seconds value of the initial date-time.
    • If frequency is not "secondly" or "minutely" and there is no byMinute property, add a byMinute property with the sole value being the minutes value of the initial date-time.
    • If frequency is not "secondly", "minutely", or "hourly" and there is no byHour property, add a byHour property with the sole value being the hours value of the initial date-time.
    • If frequency is "weekly" and there is no byDay property, add a byDay property with the sole value being the day of the week of the initial date-time.
    • If frequency is "monthly" and there is no byDay property and no byMonthDay property, add a byMonthDay property with the sole value being the day of the month of the initial date-time.
    • If frequency is "yearly" and there is no byYearDay property:
      • If there are no byMonth or byWeekNo properties, and either there is a byMonthDay property or there is no byDay property, add a byMonth property with the sole value being the month of the initial date-time.
      • If there are no byMonthDay, byWeekNo, or byDay properties, add a byMonthDay property with the sole value being the day of the month of the initial date-time.
      • If there is a byWeekNo property and no byMonthDay or byDay properties, add a byDay property with the sole value being the day of the week of the initial date-time.

4.3.4. excludedRecurrenceRules 🚫

Type: "RecurrenceRule[]" (optional)

This defines a set of recurrence rules (repeating patterns) for date-times on which the object will not occur 🙅‍♀️. The rules are interpreted the same way as the recurrenceRules property (see Section 4.3.3), with one exception: the initial date-time the rule is applied to (the "start" date-time for events or the "start" or "due" date-time for tasks) is only considered part of the expansion if it matches the rule. The resulting set of date-times is then removed from those generated by the recurrenceRules property, as described in Section 4.3.

4.3.5. recurrenceOverrides 🦋

Type: "LocalDateTime[PatchObject]" (optional)

This maps recurrence ids (the date-time produced by the recurrence rule) to the overridden properties of the recurrence instance. It's giving customization 💅

If the recurrence id doesn't match a date-time from the recurrence rule (or no rule is specified), it is to be treated as an additional occurrence (like an RDATE from iCalendar). The patch object may often be empty in this case.

If the patch object defines the excluded property of an occurrence to be true, this occurrence is omitted from the final set of recurrences for the calendar object (like an EXDATE from iCalendar). Such a patch object MUST NOT patch any other property. 🙈

By default, an occurrence inherits all properties from the main object except the start (or due) date-time, which is shifted to match the recurrence id LocalDateTime. However, individual properties of the occurrence can be modified by a patch or multiple patches. It is valid to patch the start property value, and this patch takes precedence over the value generated from the recurrence id. Both the recurrence id and the patched start date-time may occur before the original JSCalendar object's start or due date. 🕰️

A pointer in the PatchObject MUST be ignored if it starts with one of the following prefixes:

  • @type
  • excludedRecurrenceRules
  • method
  • privacy
  • prodId
  • recurrenceId
  • recurrenceIdTimeZone
  • recurrenceOverrides
  • recurrenceRules
  • relatedTo
  • replyTo
  • sentBy
  • timeZones
  • uid

4.3.6. excluded 🎀

Type: "Boolean" (optional, default: false)

This defines whether this object is an overridden, excluded instance of a recurring JSCalendar object (see Section 4.3.5). If this property value is true, this calendar object instance MUST be removed from the occurrence expansion. The absence of this property, or the presence of its default value as false, indicates that this instance MUST be included in the occurrence expansion. 💖

4.4. Sharing and Scheduling Properties 🫶

4.4.1. priority ✨

Type: "Int" (optional, default: 0) 🌸

okay so priority is how a calendar object says how important it is 💅 Scheduling systems can use it to sort out clashes when a time slot is contested, which is so useful when everyone's double-booked 😭

It's an integer from 0 to 9. 0 means the priority is undefined, and how that gets handled is up to the situation 🙈 1 is the highest priority, 2 is the second highest, and it keeps going down like that until 9, which is the lowest 🫶 Any other integer values are reserved for future use, so don't go claiming them yet 🔒

4.4.2. freeBusyStatus ⏰

Type: "String" (optional, default: "busy") 🦋

This one tells the world how this calendar object should count when someone's free-busy state is being worked out. The value MUST be one of the following, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 💖

"free": The object gets ignored when figuring out whether the user is busy. Main character energy: invisible 👻

"busy": The object gets included when figuring out whether the user is busy. Full commitment 💜

4.4.3. privacy 🔐

Type: "String" (optional, default: "public") 🧚

Calendar objects usually get grouped together and might get shared with other people 👀 The privacy property lets the owner say that the object shouldn't be shared at all, or that only the time info can be shared while the details stay hidden 🙈 Whatever API the object is accessed through is the one that actually enforces these restrictions, not the property itself 💅

This property MUST NOT affect the information sent to scheduled participants. It only gets interpreted by protocols that share one user's calendar objects with other users ✨

The value MUST be one of the following, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3). Any value the client or server doesn't understand should be preserved but treated as equivalent to "private" 🫠

"public": The full details of the object are visible to everyone the calendar is shared with. Nothing to hide here 🌈

"private": The details are hidden, and only the basic time and metadata get shared 🎀 The following properties MAY be shared. Any other properties MUST NOT be shared:

  • @type
  • created
  • due
  • duration
  • estimatedDuration
  • freeBusyStatus
  • privacy
  • recurrenceOverrides (Only patches that apply to another permissible property are allowed to be shared.)
  • sequence
  • showWithoutTime
  • start
  • timeZone
  • timeZones
  • uid
  • updated

"secret": The object is hidden completely, as though it never existed, whenever the calendar it lives in gets shared 🤫🖤

Privacy is the whole vibe. Don't leak what's supposed to be private 🔥

4.4.4. replyTo 💌

Type: "String[String]" (optional) 📮

This is the list of ways participants can send their response back to the organizer of the calendar object 🫶 The keys are the available methods, and they MUST only contain ASCII alphanumeric characters (A-Za-z0-9). Each value is a URI for the method named in its key ✨ Future methods can be defined in later specifications and registered with IANA. A calendar client MUST ignore any method it doesn't understand, but it MUST preserve the method key and URI 🧚 This property MUST be omitted if no method is defined, rather than being set to an empty object 🙅‍♀️

The following methods are defined:

"imip": The organizer accepts an iCalendar Message-Based Interoperability Protocol (iMIP) [RFC6047] response at this email address. The value MUST be a "mailto:" URI 📧

"web": Opening this URI in a web browser gives the user a page where they can submit a reply to the organizer 🌐 The value MUST be a URL using the "https:" scheme 🔒

"other": The organizer is identified by this URI, but the method for submitting the response is undefined 🤷‍♀️

4.4.5. sentBy 📬

Type: "String" (optional) 💫

This is the email address in the "From" header of the email that this calendar object arrived in 📨 It only matters if the calendar object came in through iMIP or as an attachment to a message. If it's set, the value MUST be a valid addr-spec value as defined in Section 3.4.1 of [RFC5322] 🥰

4.4.6. participants ✨

Type: "Id[Participant]" (optional) 🌸

okay so this is a map of participant ids to participants, and it tells you how each person is taking part in the calendar object 💅 think of it as the guest list for the whole event, with a little note on everyone 🫶

If this property is set and any participant has a "sendTo" property, then the "replyTo" property of this calendar object MUST define at least one reply method. no skipping this one bestie 🙅‍♀️

A Participant object has the following properties:

@type: "String" (mandatory) 🧚 this is the type label for the object. it MUST be "Participant" ✨

name: "String" (optional) 💖 the display name of the participant, like "Joe Bloggs" 🎀

email: "String" (optional) 💌 the email address you use to contact the participant, or to match them up with an address book entry. if it's set, the value MUST be a valid "addr-spec" value as defined in Section 3.4.1 of [RFC5322] 📧

description: "String" (optional) 📝 a plain-text description of this participant. this could include more info about their role in the event or how best to reach them 🌈

sendTo: "String[String]" (optional) 📮 this is the list of methods the participant can use to receive the invitation and any updates to the calendar object. ngl this one is giving multiple inboxes energy 🦋

the keys in the property value are the available methods, and they MUST only contain ASCII alphanumeric characters (A-Za-z0-9) 🔤. the value is a URI for whichever method the key names. future methods may be defined in future specifications and registered with IANA 🔮. a calendar client MUST ignore any method it does not understand, but it MUST preserve the method key and URI 🫧. this property MUST be omitted if no method is defined (rather than being specified as an empty object) 🙈

the following methods are defined:

  • "imip": the participant accepts an iMIP [RFC6047] request at this email address. the value MUST be a "mailto:" URI. it MAY be different from the value of the participant's "email" property 💜
  • "other": the participant is identified by this URI, but the method for submitting the invitation is undefined 🌙

kind: "String" (optional) 👑 this is what kind of entity the participant is, if we know 👀

this MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 🍓. any value the client or server doesn't understand should be treated the same as if this property is omitted 🫠

  • "individual": a single person 🧍‍♀️
  • "group": a collection of people invited as a whole 👯‍♀️
  • "location": a physical location that needs to be scheduled, e.g., a conference room 🏢
  • "resource": a non-human resource other than a location, such as a projector 📽️

roles: "String[Boolean]" (mandatory) 🎭 this is the set of roles this participant fulfills. it's giving main character casting ✨

at least one role MUST be specified for the participant 🎬. the keys in the set MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 🧩:

  • "owner": the participant is an owner of the object. this signifies they have permission to make changes to it that affect the other participants. nonowner participants may only change properties that affect only themselves (for example, setting their own alerts or changing their RSVP status) 🔐
  • "attendee": the participant is expected to be present at the event 🙋‍♀️
  • "optional": the participant's involvement with the event is optional. this is expected to be primarily combined with the "attendee" role 🌷
  • "informational": the participant is copied for informational reasons and is not expected to attend 📬
  • "chair": the participant is in charge of the event/task when it occurs 👸
  • "contact": the participant is someone that may be contacted for information about the event 📞

the value for each key in the map MUST be true ✅. it is expected that no more than one of the roles "attendee" and "informational" be present; if more than one are given, "attendee" takes precedence over "informational" 🥇. roles that are unknown to the implementation MUST be preserved 🫶

locationId: "Id" (optional) 📍 this is the location where this participant is expected to be attending.

if the value does not correspond to any location id in the "locations" property of the JSCalendar object, this MUST be treated the same as if the participant's locationId were omitted 🗺️

language: "String" (optional) 🌍 this is the language tag, as defined in [RFC5646], that best describes the participant's preferred language, if known 🗣️

participationStatus: "String" (optional, default: "needs-action") 🚦 this is the participation status, if any, of this participant.

the value MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 🎟️:

  • "needs-action": no status has yet been set by the participant 🫥
  • "accepted": the invited participant will participate 🥳
  • "declined": the invited participant will not participate 🙅‍♀️
  • "tentative": the invited participant may participate 🤔
  • "delegated": the invited participant has delegated their attendance to another participant, as specified in the "delegatedTo" property 🤝

participationComment: "String" (optional) 💬 this is a note from the participant that explains their participation status 🫧

expectReply: "Boolean" (optional, default: false) 📩 if true, the organizer is expecting the participant to notify them of their participation status 👀

scheduleAgent: "String" (optional, default: "server") 🤖 this is who is responsible for sending scheduling messages with this calendar object to the participant 📨

the value MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 🪄:

  • "server": the calendar server will send the scheduling messages 🖥️
  • "client": the calendar client will send the scheduling messages 📱
  • "none": no scheduling messages are to be sent to this participant 🚫

scheduleForceSend: "Boolean" (optional, default: false) 🚀 a client may set the property on a participant to true to request that the server send a scheduling message to the participant when it would not normally do so (e.g., if no significant change is made to the object or the scheduleAgent is set to client) 🫵. the property MUST NOT be stored in the JSCalendar object on the server or appear in a scheduling message 🙊

scheduleSequence: "UnsignedInt" (optional, default: 0) 🔢 this is the sequence number of the last response from the participant. if defined, this MUST be a nonnegative integer 🔢

this can be used to determine whether the participant has sent a new response following significant changes to the calendar object, and to determine if future responses are responding to a current or older view of the data 🕰️

scheduleStatus: "String[]" (optional) 📋 this is a list of status codes, returned from the processing of the most recent scheduling message sent to this participant 🧾. the status codes MUST be valid "statcode" values as defined in the ABNF in Section 3.8.8.3 of [RFC5545] 🔡

servers MUST only add or change this property when they send a scheduling message to the participant 🖨️. clients SHOULD NOT change or remove this property if it was provided by the server 🙏. clients MAY add, change, or remove the property for participants where the client is handling the scheduling 🛠️

this property MUST NOT be included in scheduling messages. keep it out of the mail, bestie 💌

scheduleUpdated: "UTCDateTime" (optional) ⏰ this is the timestamp for the most recent response from this participant 🕓

this is the "updated" property of the last response when using iTIP. it can be compared to the "updated" property in future responses to detect and discard older responses delivered out of order 🗑️

sentBy: "String" (optional) 📤 this is the email address in the "From" header of the email that last updated this participant via iMIP 💌. this SHOULD only be set if the email address is different to the one in the mailto URI of this participant's "imip" method in the "sendTo" property (i.e., the response was received from a different address to the one the invitation was sent to) 🕵️‍♀️. if set, the value MUST be a valid "addr-spec" value as defined in Section 3.4.1 of [RFC5322] 📧

invitedBy: "Id" (optional) 🎟️ this is the id of the participant who added this participant to the event/task, if known 🫂

delegatedTo: "Id[Boolean]" (optional) 🤲 this is the set of participant ids that this participant has delegated their participation to 🧳. each key in the set MUST be the id of a participant 🔑. the value for each key in the map MUST be true 💯. if there are no delegates, this MUST be omitted (rather than specified as an empty set) 🙃

delegatedFrom: "Id[Boolean]" (optional) 🫱 this is a set of participant ids that this participant is acting as a delegate for 🎀. each key in the set MUST be the id of a participant 🔑. the value for each key in the map MUST be true 💯. if there are no delegators, this MUST be omitted (rather than specified as an empty set) 🙃

memberOf: "Id[Boolean]" (optional) 👥 this is a set of group participants that were invited to this calendar object, which caused this participant to be invited due to their membership in the group(s) 🪪. each key in the set MUST be the id of a participant 🔑. the value for each key in the map MUST be true 💯. if there are no groups, this MUST be omitted (rather than specified as an empty set) 🙃

links: "Id[Link]" (optional) 🔗 this is a map of link ids to Link objects, representing external resources associated with this participant, for example, a vCard or image 🖼️. if there are no links, this MUST be omitted (rather than specified as an empty set) 🙃

progress: "String" (optional; only allowed for participants of a Task) 📈 this represents the progress of the participant for this task 🏃‍♀️. it MUST NOT be set if the "participationStatus" of this participant is any value other than "accepted" 🚫. see Section 5.2.5 for allowed values and semantics ✨

progressUpdated: "UTCDateTime" (optional; only allowed for participants of a Task) 🕰️ this specifies the date-time the "progress" property was last set on this participant 📅. see Section 5.2.6 for allowed values and semantics 💅

percentComplete: "UnsignedInt" (optional; only allowed for participants of a Task) 💯 this represents the percent completion of the participant for this task 🎉. the property value MUST be a positive integer between 0 and 100 🌈

4.4.7. requestStatus 💌

Type: "String" (optional)

okay so this one is the request status 🎀. It's what comes back after the most recent scheduling request for this JSCalendar object gets processed. The allowed values are defined by the ABNF for statcode, statdesc and extdata in Section 3.8.8.3 of [RFC5545], plus this ABNF from [RFC5234]:

reqstatus = statcode ";" statdesc [";" extdata]

Servers MUST only add or change this property when they perform a scheduling action 💅. Clients SHOULD NOT change or remove it if the server provided it 🫶. Clients MAY add, change, or remove it when the client is the one handling the scheduling 🔥.

This property MUST only be included in scheduling messages following the rules for the REQUEST-STATUS iCalendar property in [RFC5546] 📬.

4.5. Alerts Properties 🔔

4.5.1. useDefaultAlerts

Type: "Boolean" (optional, default: false)

If true, the app uses the user's default alerts and ignores the alerts property 🙈. Fetching those defaults depends on the API this JSCalendar object came from, and this spec doesn't define how that works. If an implementation can't figure out the user's default alerts, or none are set, it MUST process the alerts property as if useDefaultAlerts were false 💖.

4.5.2. alerts

Type: "Id[Alert]" (optional)

This is a map of alert ids to Alert objects 🌸. It stores the alerts and reminders to show or send to the user for this calendar object.

An Alert object has these properties:

  • @type: "String" (mandatory)
    • This specifies the type of this object. This MUST be "Alert" 💜.
  • trigger: "OffsetTrigger|AbsoluteTrigger|UnknownTrigger" (mandatory)
    • This decides when the alert goes off. New types may be defined in future documents 🦋.
    • An "OffsetTrigger" object has these properties:
      • @type: "String" (mandatory)
        • This specifies the type of this object. This MUST be "OffsetTrigger" ✨.
      • offset: "SignedDuration" (mandatory)
        • This is the offset from the time property named in the alert's relativeTo property. Negative durations mean the alert goes off before that time, and positive durations mean after it 🕰️.
      • relativeTo: "String" (optional, default: "start")
        • This says which time property the offset is measured from. The value MUST be one of the following:
          • "start": triggers the alert relative to the start of the calendar object 🌅
          • "end": triggers the alert relative to the end/due time of the calendar object 🌇
    • An "AbsoluteTrigger" object has these properties:
      • @type: "String" (mandatory)
        • This specifies the type of this object. This MUST be "AbsoluteTrigger" 🎯.
      • when: "UTCDateTime" (mandatory)
        • This is the exact UTC date-time the alert goes off 🗓️.
    • An "UnknownTrigger" object is one with an "@type" property whose value isn't recognised (so, not "OffsetTrigger" or "AbsoluteTrigger"), plus zero or more other properties. It's there for compatibility with client extensions and future specifications 🧩. Implementations SHOULD NOT trigger for trigger types they don't understand, but they MUST preserve them 🫧.
  • acknowledged: "UTCDateTime" (optional)
    • This records when an alert was last acknowledged 👀. It gets set when the user dismisses the alert. Other clients that sync this property SHOULD automatically dismiss or suppress duplicate alerts (alerts with the same alert id that triggered on or before this date-time) 🧹.
    • For a recurring calendar object, setting acknowledged MUST NOT add a new override to the recurrenceOverrides property. If the alert isn't already overridden, the acknowledged property MUST be set on the alert in the base event/task 🔁.
    • Some kinds of alert action don't tell you when the user actually sees them, like email-based alerts. For those, this property MUST be set right when the alert triggers and the action is carried out successfully 📧.
  • relatedTo: "String[Relation]" (optional)
    • This links this alert to other alerts in the same JSCalendar object 🔗. If the user wants to snooze an alert, the application MUST create a new alert that triggers after the snooze. That new snooze alert MUST set a parent relation pointing at the identifier of the original alert 😴.
  • action: "String" (optional, default: "display")
    • This describes how to alert the user 📣.
    • The value MUST be at most one of the following values, a value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 🏷️:
      • "display": The alert should be displayed in whatever way suits the current device and user context 📱.
      • "email": The alert should trigger an email sent to the user, letting them know about the alert. This action is usually only a good fit for server implementations 💌.

4.6. Multilingual Properties 🌍

4.6.1. localizations

Type: "String[PatchObject]" (optional)

This is a map where each key is a language tag [RFC5646], and each value is a set of patches to apply to the calendar object so it gets localised into that locale 🗣️.

Check out the description of PatchObject (Section 1.4.9) for the structure of a PatchObject. The patches are applied to the top-level calendar object. On top of that, the locale property of the patched object is set to the language tag 🏳️‍🌈. Every pointer for a patch MUST end with one of these suffixes. Any patch that doesn't follow this MUST be ignored, unless a future RFC says otherwise 🚫:

  • title
  • description
  • name

A patch MUST NOT have the prefix recurrenceOverrides. Any localisation of an override MUST be a patch to the localizations property inside the override instead 🧁. For example, a patch to locations/abcd1234/title is fine, but a patch to uid or recurrenceOverrides/2020-01-05T14:00:00/title is not 🙅‍♀️.

Heads up, this spec doesn't define how to keep localised content valid 🤓. For example, if a client app changes a JSCalendar object's title property, it might also need to update any localisations of that property. Client implementations SHOULD provide ways to manage localizations, but how that's done depends on the app's workflow and requirements 🛠️.

4.7. Time Zone Properties ⏰

4.7.1. timeZone

Type: "TimeZoneId|null" (optional, default: null)

This identifies the time zone the object is scheduled in, or is null for floating time 🌙. It's either a name from the IANA Time Zone Database [TZDB], or the TimeZoneId of a custom time zone from the timeZones property (Section 4.7.2). If it's omitted, it MUST be presumed to be null (i.e., floating time) 🫠.

4.7.2. timeZones

Type: "TimeZoneId[TimeZone]" (optional)

This maps identifiers of custom time zones to their time zone definitions 🗺️. Each key in the map has these restrictions:

  • To avoid clashing with names in the IANA Time Zone Database [TZDB], it MUST start with the / character 🚧.
  • It MUST be a valid paramtext value, as specified in Section 3.1 of [RFC5545] 📝.
  • At least one other property in the same JSCalendar object MUST reference a time zone using this identifier. (In other words, orphaned time zones are not allowed 🙅‍♀️.)

An identifier only needs to be unique within this JSCalendar object. It MAY differ from the tzId property value of the TimeZone object it maps to 🌀.

A JSCalendar object can be part of a hierarchy of other JSCalendar objects (say, an Event is an entry in a Group). In that case, the set of time zones is the sum of the time zone definitions of this object and its parent objects 🌳. If several time zones share the same identifier, the definition closest to the calendar object (in relation to its parents) MUST be used. (For an Event, a time zone definition in its timeZones property beats a definition with the same id in the Group 🥇.) Time zone definitions in any children of the calendar object MUST be ignored 🙈.

A TimeZone object maps a VTIMEZONE component from iCalendar, and its semantics are as defined in [RFC5545]. A valid time zone MUST define at least one transition rule in the standard or daylight property 🌞🌚. Its properties are:

  • @type: "String" (mandatory)
    • This specifies the type of this object. This MUST be "TimeZone" 💜.
  • tzId: "String" (mandatory)
    • This is the TZID property from iCalendar. Note that this means the value MUST be a valid paramtext value, as specified in Section 3.1. of [RFC5545] 🆔.
  • updated: "UTCDateTime" (optional)
    • This is the LAST-MODIFIED property from iCalendar 🕓.
  • url: "String" (optional)
    • This is the TZURL property from iCalendar 🔗.
  • validUntil: "UTCDateTime" (optional)
    • This is the TZUNTIL property from iCalendar, specified in [RFC7808] 🏁.
  • aliases: "String[Boolean]" (optional)
    • This maps the TZID-ALIAS-OF properties from iCalendar, specified in [RFC7808], to a JSON set of aliases 👯. The set is represented as an object, with the aliases as keys. The value for each key in the map MUST be true ✅.
  • standard: "TimeZoneRule[]" (optional)
    • This is the STANDARD sub-components from iCalendar. The order MUST be preserved during conversion 📚.
  • daylight: "TimeZoneRule[]" (optional)
    • This is the DAYLIGHT sub-components from iCalendar. The order MUST be preserved during conversion ☀️.

A TimeZoneRule object maps a STANDARD or DAYLIGHT sub-component from iCalendar, with the restriction that at most one recurrence rule is allowed per rule 🧠. It has these properties:

  • @type: "String" (mandatory)
    • This specifies the type of this object. This MUST be "TimeZoneRule" 💅.
  • start: "LocalDateTime" (mandatory)
    • This is the DTSTART property from iCalendar 🌱.
  • offsetFrom: "String" (mandatory)
    • This is the TZOFFSETFROM property from iCalendar ⬅️.
  • offsetTo: "String" (mandatory)
    • This is the TZOFFSETTO property from iCalendar ➡️.
  • recurrenceRules: "RecurrenceRule[]" (optional)
    • This is the RRULE property mapped, as specified in Section 4.3.3 🔁. While evaluating the recurrence rule, the "until" property value MUST be interpreted as a local time in the UTC time zone 🌐.
  • recurrenceOverrides: "LocalDateTime[PatchObject]" (optional)
    • This maps the RDATE properties from iCalendar 📅. The set is represented as an object, with the recurrence dates as keys. The patch object MUST be the empty JSON object ({}) 🫙.
  • names: "String[Boolean]" optional)
    • This maps the TZNAME properties from iCalendar to a JSON set 🏷️. The set is represented as an object, with the names as keys, leaving out any tznparam component from iCalendar. The value for each key in the map MUST be true ✅.
  • comments: "String[]" (optional)
    • This maps the COMMENT properties from iCalendar 💬. The order MUST be preserved during conversion 🧾.

5. Type-Specific JSCalendar Properties ✨

5.1. Event Properties 🎉

In addition to the common JSCalendar object properties (Section 4), an Event has these properties:

5.1.1. start

Type: "LocalDateTime" (mandatory)

This is the date and time the event starts, in the event's time zone (as set in the timeZone property, see Section 4.7.1) 🌟.

5.1.2. duration

Type: "Duration" (optional, default: "PT0S") 🌸

okay bestie, duration is how long the event lasts, and it's always zero or positive ⏰ It's measured in the event's start time zone, so it's giving clarity 💅 And the end time? Just add the duration to the start time. Easy peasy ✨

An Event MAY involve start and end locations that are in different time zones (think a transcontinental flight ✈️). You can express that with the relativeTo and timeZone properties of the Event's Location objects (see Section 4.2.5) 🌍

5.1.3. status

Type: "String" (optional, default: "confirmed") 🎀

This is the scheduling status (Section 4.4) of an Event. If it's set, it MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 💖

  • "confirmed": indicates the event is definitely happening 🙌
  • "cancelled": indicates the event has been cancelled 💀
  • "tentative": indicates the event may happen 🦋

5.2. Task Properties

In addition to the common JSCalendar object properties (Section 4), a Task has the following properties 📝

5.2.1. due

Type: "LocalDateTime" (optional) ⏳

This is the date/time the task is due, in the task's time zone 🗓️

5.2.2. start

Type: "LocalDateTime" (optional) 🚀

This is the date/time the task should start, in the task's time zone 🌷

5.2.3. estimatedDuration

Type: "Duration" (optional) ⏱️

This specifies the estimated positive duration of time the task takes to complete. Main character planning energy 🧚

5.2.4. percentComplete

Type: "UnsignedInt" (optional) 📊

This represents the percent completion of the task overall. The property value MUST be a positive integer between 0 and 100 💯

5.2.5. progress

Type: "String" (optional) 🌈

This defines the progress of this task. If it's omitted, the default progress (Section 4.4) of a Task is defined as follows, in order of evaluation 🔍

  1. "completed": if the "progress" property value of all participants is "completed" 🎉
  2. "failed": if at least one "progress" property value of a participant is "failed" 😭
  3. "in-process": if at least one "progress" property value of a participant is "in-process" 🏃‍♀️
  4. "needs-action": if none of the other criteria match 📌

If it's set, it MUST be one of the following values, another value registered in the IANA "JSCalendar Enum Values" registry, or a vendor-specific value (see Section 3.3) 🫶

  • "needs-action": indicates the task needs action 👀
  • "in-process": indicates the task is in process 🔥
  • "completed": indicates the task is completed ✅
  • "failed": indicates the task failed 💔
  • "cancelled": indicates the task was cancelled 🫠

5.2.6. progressUpdated

Type: "UTCDateTime" (optional) 🕰️

This specifies the date/time the "progress" property of either the task overall (Section 5.2.5) or a specific participant (Section 4.4.6) was last updated. Receipts, bestie 🧾

If the task is recurring and has future instances, a client may want to keep track of the last progress update timestamp of one specific task recurrence but leave the other instances unchanged. One way to do that is by overriding the "progressUpdated" property in the task "recurrenceOverrides" property. However, this could produce a long list of timestamps for regularly recurring tasks 📜😵‍💫 An alternative approach is to split the Task into a current, single instance of Task with this instance's progress update time, plus a future recurring instance. See also Section 4.1.3 on splitting ✂️✨

5.3. Group Properties

Group supports the following common JSCalendar properties (Section 4) 🗂️

  • @type
  • uid
  • prodId
  • created
  • updated
  • title
  • description
  • descriptionContentType
  • links
  • locale
  • keywords
  • categories
  • color
  • timeZones

In addition, the following Group-specific properties are supported 💜

5.3.1. entries

Type: "(Task|Event)[]" (mandatory) 🧺

This is a collection of group members. Implementations MUST ignore entries of unknown type. Not them bringing in mystery entries 🙅‍♀️

5.3.2. source

Type: "String" (optional) 🌐

This is the source from which updated versions of this group may be retrieved. The value MUST be a URI 🔗

6. Examples ✨

The following examples illustrate several aspects of the JSCalendar data model and format 🎀 The examples may omit mandatory or additional properties, which is indicated by a placeholder property with the key "...". While most of the examples use calendar event objects, they are also illustrative for tasks 🦋

6.1. Simple Event

This example illustrates a simple one-time event. It specifies a one-time event that begins on January 15, 2020 at 1 pm New York local time and ends after 1 hour 🗽

{
  "@type": "Event",
  "uid": "a8df6573-0474-496d-8496-033ad45d7fea",
  "updated": "2020-01-02T18:23:04Z",
  "title": "Some event",
  "start": "2020-01-15T13:00:00",
  "timeZone": "America/New_York",
  "duration": "PT1H"
}

6.2. Simple Task

This example illustrates a simple task for a plain to-do item 📝

{
  "@type": "Task",
  "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f2",
  "updated": "2020-01-09T14:32:01Z",
  "title": "Do something"
}

6.3. Simple Group

This example illustrates a simple calendar object group that contains an event and a task 🧺💖

{
  "@type": "Group",
  "uid": "bf0ac22b-4989-4caf-9ebd-54301b4ee51a",
  "updated": "2020-01-15T18:00:00Z",
  "name": "A simple group",
  "entries": [{
    "@type": "Event",
    "uid": "a8df6573-0474-496d-8496-033ad45d7fea",
    "updated": "2020-01-02T18:23:04Z",
    "title": "Some event",
    "start": "2020-01-15T13:00:00",
    "timeZone": "America/New_York",
    "duration": "PT1H"
  },
  {
    "@type": "Task",
    "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f2",
    "updated": "2020-01-09T14:32:01Z",
    "title": "Do something"
  }]
}

6.4. All-Day Event

This example illustrates an event for an international holiday 🃏 It specifies an all-day event on April 1 that occurs every year since the year 1900 🤡

{
  "...": "",
  "title": "April Fool's Day",
  "showWithoutTime": true,
  "start": "1900-04-01T00:00:00",
  "duration": "P1D",
  "recurrenceRules": [{
    "@type": "RecurrenceRule",
    "frequency": "yearly"
  }]
}

6.5. Task with a Due Date

This example illustrates a task with a due date 🛒 It's a reminder to buy groceries before 6 pm Vienna local time on January 19, 2020. The calendar user expects to need 1 hour for shopping 🍓

{
  "...": "",
  "title": "Buy groceries",
  "due": "2020-01-19T18:00:00",
  "timeZone": "Europe/Vienna",
  "estimatedDuration": "PT1H"
}

6.6. Event with End Time Zone

This example illustrates the use of end time zones with an international flight ✈️🌏 The flight starts on April 1, 2020 at 9 am in Berlin local time. The duration of the flight is scheduled at 10 hours 30 minutes. The time at the flight's destination is in the same time zone as Tokyo. Calendar clients could use the end time zone to display the arrival time in Tokyo local time and highlight the time zone difference of the flight 🗾 The location names can serve as input for navigation systems 🧭

{
  "...": "",
  "title": "Flight XY51 to Tokyo",
  "start": "2020-04-01T09:00:00",
  "timeZone": "Europe/Berlin",
  "duration": "PT10H30M",
  "locations": {
    "1": {
      "@type": "Location",
      "rel": "start",
      "name": "Frankfurt Airport (FRA)"
    },
    "2": {
      "@type": "Location",
      "rel": "end",
      "name": "Narita International Airport (NRT)",
      "timeZone": "Asia/Tokyo"
    }
  }
}

6.7. Floating-Time Event (with Recurrence)

This example illustrates the use of floating time 🌙 Since January 1, 2020, a calendar user blocks 30 minutes every day to practice yoga at 7 am local time, in whatever time zone the user is located on that date 🧘‍♀️🌸

{
  "...": "",
  "title": "Yoga",
  "start": "2020-01-01T07:00:00",
  "duration": "PT30M",
  "recurrenceRules": [{
    "@type": "RecurrenceRule",
    "frequency": "daily"
  }]
}

6.8. Event with Multiple Locations and Localization

This example illustrates an event that happens at both a physical and a virtual location 🎤 Fans can see a live concert on premises or online. The event title and descriptions are localized 🌈

{
  "...": "",
  "title": "Live from Music Bowl: The Band",
  "description": "Go see the biggest music event ever!",
  "locale": "en",
  "start": "2020-07-04T17:00:00",
  "timeZone": "America/New_York",
  "duration": "PT3H",
  "locations": {
    "c0503d30-8c50-4372-87b5-7657e8e0fedd": {
      "@type": "Location",
      "name": "The Music Bowl",
      "description": "Music Bowl, Central Park, New York",
      "coordinates": "geo:40.7829,-73.9654"
    }
  },
  "virtualLocations": {
    "vloc1": {
      "@type": "VirtualLocation",
      "name": "Free live Stream from Music Bowl",
      "uri": "https://stream.example.com/the_band_2020"
    }
  },
  "localizations": {
    "de": {
      "title": "Live von der Music Bowl: The Band!",
      "description": "Schau dir das größte Musikereignis an!",
      "virtualLocations/vloc1/name":
        "Gratis Live-Stream aus der Music Bowl"
    }
  }
}

6.9. Recurring Event with Overrides

This example illustrates the use of recurrence overrides 🔁 A math course at a university is held for the first time on January 8, 2020 at 9 am London time and occurs every week until June 24, 2020. Each lecture lasts for one hour and 30 minutes and is located at the Mathematics department 📐 This event has exceptional occurrences: the last occurrence of the course is an exam, which lasts for 2 hours and starts at 10 am 😱 Also, the location of the exam differs from the usual location. On April 1, no course is held 🏖️ On January 7 at 2 pm, there is an optional introduction course, which occurs before the first regular lecture 🫶

{
  "...": "",
  "title": "Calculus I",
  "start": "2020-01-08T09:00:00",
  "timeZone": "Europe/London",
  "duration": "PT1H30M",
  "locations": {
    "mlab": {
      "@type": "Location",
      "title": "Math lab room 1",
      "description": "Math Lab I, Department of Mathematics"
    }
  },
  "recurrenceRules": [{
    "@type": "RecurrenceRule",
    "frequency": "weekly",
    "until": "2020-06-24T09:00:00"
  }],
  "recurrenceOverrides": {
    "2020-01-07T14:00:00": {
      "title": "Introduction to Calculus I (optional)"
    },
    "2020-04-01T09:00:00": {
      "excluded": true
    },
    "2020-06-25T09:00:00": {
      "title": "Calculus I Exam",
      "start": "2020-06-25T10:00:00",
      "duration": "PT2H",
      "locations": {
        "auditorium": {
          "@type": "Location",
          "title": "Big Auditorium",
          "description": "Big Auditorium, Other Road"
        }
      }
    }
  }
}

6.10. Recurring Event with Participants 🎀

okay so this one is a whole team meeting energy example 🧚 A team meeting happens every week starting January 8, 2020, at 9 am Johannesburg time. The event owner also chairs it, and everyone meets in a virtual room. One attendee already accepted the invite, but on March 4, 2020, he's unavailable and declines just that one occurrence 💅

{
  "...": "",
  "title": "FooBar team meeting",
  "start": "2020-01-08T09:00:00",
  "timeZone": "Africa/Johannesburg",
  "duration": "PT1H",
  "virtualLocations": {
    "0": {
      "@type": "VirtualLocation",
      "name": "ChatMe meeting room",
      "uri": "https://chatme.example.com?id=1234567&pw=a8a24627b63d"
    }
  },
  "recurrenceRules": [{
    "@type": "RecurrenceRule",
    "frequency": "weekly"
  }],
  "replyTo": {
    "imip": "mailto:f245f875-7f63-4a5e-a2c8@schedule.example.com"
  },
  "participants": {
    "dG9tQGZvb2Jhci5xlLmNvbQ": {
      "@type": "Participant",
      "name": "Tom Tool",
      "email": "tom@foobar.example.com",
      "sendTo": {
        "imip": "mailto:tom@calendar.example.com"
      },
      "participationStatus": "accepted",
      "roles": {
        "attendee": true
      }
    },
    "em9lQGZvb2GFtcGxlLmNvbQ": {
      "@type": "Participant",
      "name": "Zoe Zelda",
      "email": "zoe@foobar.example.com",
      "sendTo": {
        "imip": "mailto:zoe@foobar.example.com"
      },
      "participationStatus": "accepted",
      "roles": {
        "owner": true,
        "attendee": true,
        "chair": true
      }
    }
  },
  "recurrenceOverrides": {
    "2020-03-04T09:00:00": {
      "participants/dG9tQGZvb2Jhci5xlLmNvbQ/participationStatus":
                                                          "declined"
    }
  }
}

7. Security Considerations 🔐

okay bestie, this part is serious 😭 Calendar and scheduling info is super privacy sensitive. It can reveal someone's social network, their location and the location of the people around them, identity and credential info, and their patterns of behavior in both the physical and cyber worlds 🙈 Calendar events and tasks can even influence where a user physically is, or what they do online, within a known time window. So the data has to be transmitted and stored carefully to protect it from threats like eavesdropping, replay, message insertion, deletion, modification, and on-path attacks 🛡️

The stuff being stored and sent can also show up in systems with real-world consequences 💀 Think a home automation system that turns an alarm on and off, or a coworking space that charges the organizer of an event for booking one of its meeting rooms. Those systems need to be careful to authenticate all the data they receive, so nobody can subvert them and the change is confirmed to come from an authorized entity 🔥

This document only defines the data format, so most of these concerns belong to the API, or to however the files are stored and transmitted 💜

7.1. Expanding Recurrences 🔁

a recurrence rule can produce infinite occurrences of an event, so implementations MUST handle expansions carefully to prevent accidental or deliberate resource exhaustion 😱

flip side: a recurrence rule can also be written so it expands to nothing 🙃 You can't always spot that with static analysis, so implementations MUST be careful to avoid getting stuck in infinite loops or otherwise exhausting resources while searching for the next occurrence.

events recur in the event's time zone 🌍 If the user is in a different time zone, daylight saving transitions can make an event that usually lands at 9 am suddenly shift an hour earlier. Someone could use that to try to get a participant to miss an important meeting 🙅‍♀️ So user agents must be careful to translate date-times correctly between time zones, and they may wish to call out unexpected changes in the time of a recurring event ✨

7.2. JSON Parsing 🧾

the security considerations of [RFC8259] apply to using JSON as the data interchange format 💅

like with any serialization format, parsers need to thoroughly check the syntax of the data they're given 🔍 JSON uses opening and closing tags for several types and structures, and the end of the supplied data can be reached while scanning for a matching closing tag. That's an error condition, so implementations need to stop scanning at the end of the supplied data 🛑

JSON also uses a string encoding with some escape sequences to encode special characters inside a string. Processing them takes care: make sure each escape sequence is fully formed before the special processing kicks in. Be extra careful when escape sequences sit next to other unescaped special characters, or right up against the end of the data (like in the paragraph above) 🥹

if you're parsing JSON into a non-textual structured data format, implementations may need to allocate storage to hold JSON string elements. JSON doesn't use explicit string lengths, so the risk of denial of service from resource exhaustion is small. Still, implementations may wish to put limits on how big an allocation they'll make in any given context, so untrusted data can't cause excessive memory allocation 🫶

7.3. URI Values 🌐

several JSCalendar properties hold URIs as values, and processing those properties needs extra care 👀 Section 7 of [RFC3986] discusses security risks related to URIs.

fetching remote resources carries inherent risks ⚠️ Connections must only be allowed on well-known ports, using allowed protocols (generally just HTTP/HTTPS on their default ports). The URL must be resolved externally and must not be allowed to access internal resources. Connecting to an external source also reveals IP information, which often means location too 📍

a maliciously constructed JSCalendar object can contain a huge number of URIs 😤 For published calendars with lots of subscribers, objects like that could get widely distributed. So implementations should be careful to limit automatic fetching of linked resources, to reduce the risk of it becoming an amplification vector for a denial-of-service attack 🚫

7.4. Spam 🗑️

calendar systems may receive JSCalendar files from untrusted sources, especially as attachments to emails. That's a sneaky way for an attacker to inject spam into a user's calendar 😒 It can confuse, annoy, and mislead users, or bury them in bogus events so they can't see the legit ones.

heuristic, statistical, or machine-learning-based filters can be effective at catching spam ✨ Authentication mechanisms like DomainKeys Identified Mail (DKIM) [RFC6376] can help establish where messages came from, and link the data to existing relationships, like an address book contact. Still, misclassifications are always possible, so providing a way for users to quickly correct them is advised 🙏

confusable unicode characters can be used to trick a user into trusting a JSCalendar file that looks like it's from a known contact but actually comes from a similar-looking source controlled by an attacker 🥸

7.5. Duplication 👯

it's important for calendar systems to keep the UID of an event when they update it, so you don't get accidental duplicates 📅 Consumers of the data may not remove the previous version if it has a different UID. That leads to a confusing mess of variations of the same event with no hint about which one is right 🤯 Consumers must take care to remove old events where possible, so the sheer volume of data doesn't cause an accidental denial-of-service attack 💀

7.6. Time Zones ⏰

events recur in a particular time zone. When that's different from the user's current time zone, an occurrence can unexpectedly shift for that user because of a daylight savings change in the event's time zone 🌓 A maliciously crafted event could try to confuse users like this so a meeting gets missed. Not it 🙅‍♀️

8. IANA Considerations 🌸

8.1. Media Type Registration 💖

this section defines a media type for JSCalendar data formatted in JSON. Here's the full registration template, copied exactly as written:

   This document defines a media type for use with JSCalendar data
   formatted in JSON.

   Type name:  application

   Subtype name:  jscalendar+json

   Required parameters:  type

      The "type" parameter conveys the type of the JSCalendar data in
      the body part.  The allowed parameter values correspond to the
      "@type" property of the JSON-formatted JSCalendar object in the
      body:

      "event":  The "@type" property value MUST be "Event".

      "task":  The "@type" property value MUST be "Task".

      "group":  The "@type" property value MUST be "Group".

      No other parameter values are allowed.  The parameter MUST NOT
      occur more than once.

   Optional parameters:  none

   Encoding considerations:  This is the same as the encoding
      considerations of application/json, as specified in Section 11 of
      [RFC8259].

   Security considerations:  See Section 7 of this document.

   Interoperability considerations:  While JSCalendar is designed to
      avoid ambiguities as much as possible, when converting objects
      from other calendar formats to/from JSCalendar, it is possible
      that differing representations for the same logical data or
      ambiguities in interpretation might arise.  The semantic
      equivalence of two JSCalendar objects may be determined
      differently by different applications, for example, where URL
      values differ in case between the two objects.

   Published specification:  RFC 8984

   Applications that use this media type:  Applications that currently
      make use of the text/calendar and application/calendar+json media
      types can use this as an alternative.  Similarly, applications
      that use the application/json media type to transfer calendaring
      data can use this to further specify the content.

   Fragment identifier considerations:  A JSON Pointer fragment
      identifier may be used, as defined in [RFC6901], Section 6.

   Additional information:  Magic number(s):  N/A

                            File extensions(s):  N/A

                            Macintosh file type code(s):  N/A

   Person & email address to contact for further information:
      calsify@ietf.org

   Intended usage:  COMMON

   Restrictions on usage:  N/A

   Author:  See the "Author's Address" section of this document.

   Change controller:  IETF

the big takeaway: the type parameter has three allowed values, event, task, and group 🎀 Each one has to match the @type property of the JSON object in the body. The type parameter MUST NOT occur more than once, and no other values are allowed 🙅‍♀️ The encoding matches application/json (per Section 11 of [RFC8259]), the security stuff points back to Section 7 🔗, and the interop notes say that converting from other calendar formats can produce differing representations of the same data, so two JSCalendar objects might be judged equivalent differently by different apps 🥹

the contact is calsify@ietf.org, and the change controller is IETF 💜 That's the whole registration, bestie ✨

8.2. Creation of the "JSCalendar Properties" Registry ✨

okay bestie, IANA made a "JSCalendar Properties" registry 🗂️ so that extensions to JSCalendar objects can actually interoperate 🫶 this is the kind of organisation I live for.

This registry follows the Expert Review process ([RFC8126], Section 4.5). If the "Intended Usage" field is "common", you gotta have sufficient documentation so everyone can interoperate. Preliminary community review for this registry is optional but strongly encouraged 💜.

A registration can have an intended usage of "common", "reserved", or "obsolete" 🌈. IANA lists the common ones prominently and separately from the rest, so they're easy to spot. ✨

A "reserved" registration just claims a property name without giving it any semantics 🔒. The point is to avoid name collisions with future extensions or protocol use.

An "obsolete" registration marks a property that up-to-date systems aren't expected to add anymore 🦖. A newer property has probably been defined to cover the same semantics, so it's basically a "we moved on" label 💀.

The JSCalendar property registration procedure isn't a formal standards process 🙈. It's more of an administrative procedure that lets the community comment and checks that everything is coherent, without dragging things out for ages ⏩. It's designed to encourage vendors to document and register new properties they add for use cases the original spec didn't cover, which leads to better interoperability 🎀.

8.2.1. Preliminary Community Review 🦋

Notice of a potential new registration SHOULD be sent to the Calext mailing list <calsify@ietf.org> for review 📬. That list is the right place to ask the community for feedback on a proposed new property.

Property registrations must be marked with their intended use: "common", "reserved", or "obsolete" 🏷️.

The whole point of posting publicly to that list is to get comments on the choice of property name, whether the specification document is unambiguous, and any interoperability or security considerations 🔍. The submitter may submit a revised registration proposal or abandon the registration completely at any time 🫠. no pressure, bestie 💅.

8.2.2. Submit Request to IANA 📮

Registration requests can be sent to <iana@iana.org> 💌.

8.2.3. Designated Expert Review 🧐

The main job of the designated expert (DE) is preventing name collisions and encouraging the submitter to document security and privacy considerations 🔐. For a common-use registration, the DE is expected to confirm that suitable documentation, as described in Section 4.6 of [RFC8126], is available to ensure interoperability. That documentation will usually be an RFC 📜, but simple definitions can use a web or wiki page, and if a sentence or two is deemed sufficient, it can go right in the registry itself. The DE should also verify that the property name doesn't conflict with work that's active or already published within the IETF 👀. A published specification isn't required for reserved or obsolete registrations, so those are way more chill 😌.

The DE will either approve or deny the registration request, then publish a notice of the decision to the Calext WG mailing list or its successor, and also inform IANA 📣. A denial notice must be justified with an explanation, and where it's possible, concrete suggestions on how to modify the request so it becomes acceptable should be provided 🛠️. constructive feedback is iconic 🌸.

8.2.4. Change Procedures 🔄

Once a JSCalendar property has been published by IANA, the change controller may request a change to its definition ✏️. The same procedure that would be appropriate for the original registration request is used to process a change request.

JSCalendar property registrations may not be deleted 🙅‍♀️. Properties that are no longer believed appropriate for use can be declared obsolete by changing their "intended usage" field, and those properties will be clearly marked in the IANA registry 🪦.

Significant changes to a JSCalendar property's definition should only be requested when there are serious omissions or errors in the published specification 🚨, because those changes may cause interoperability issues. When review is required, a change request may be denied if it makes entities that were valid under the previous definition invalid under the new one ❌.

The owner of a JSCalendar property can pass responsibility to another person or agency by informing IANA 🤝. This can be done without discussion or review, which is very low-key drama 🎀.

8.2.5. "JSCalendar Properties" Registry Template 📋

Property Name: This is the name of the property. The property name MUST NOT already be registered for any of the object types listed in the "Property Context" field of this registration 🚫. Other object types MAY already have registered a different property with the same name 🤷‍♀️; however, the same name SHOULD only be used when the semantics are analogous 💖.

Property Type: This is the type of this property, using type signatures, as specified in Section 1.3 🧩. The property type MUST be registered in the "JSCalendar Types" registry 🗃️.

Property Context: This is a comma-separated list of JSCalendar object types this property is allowed on 🍓.

Reference or Description: This is a brief description or RFC number and section reference where the property is specified (omitted for "reserved" property names) 📖.

Intended Usage: This may be "common", "reserved", or "obsolete" 🏷️.

Change Controller: This is who may request a change to this entry's definition ("IETF" for RFCs from the IETF stream) 👑.

8.2.6. Initial Contents for the "JSCalendar Properties" Registry 🌈

The following table lists the initial entries of the "JSCalendar Properties" registry 🧁. All properties are for common use 💅. All RFC section references are for this document 📚. The change controller for all these properties is "IETF" 👑✨.

okay bestie, the registry table is still going 💅✨ Here's the next chunk of initial contents for the "JSCalendar Properties" registry, with the property names, types, contexts, and where each one gets described 🎀

   +====================+=================+================+===========+
   |Property Name       |Property Type    |Property Context|Reference  |
   |                    |                 |                |or         |
   |                    |                 |                |Description|
   +====================+=================+================+===========+
   |@type               |String           |Event, Task,    |Section    |
   |                    |                 |Group,          |4.1.1,     |
   |                    |                 |AbsoluteTrigger,|Section    |
   |                    |                 |Alert, Link,    |4.5.2,     |
   |                    |                 |Location, NDay, |Section    |
   |                    |                 |OffsetTrigger,  |1.4.11,    |
   |                    |                 |Participant,    |Section    |
   |                    |                 |RecurrenceRule, |4.2.5,     |
   |                    |                 |Relation,       |Section    |
   |                    |                 |TimeZone,       |4.4.6,     |
   |                    |                 |TimeZoneRule,   |Section    |
   |                    |                 |VirtualLocation |4.3.3,     |
   |                    |                 |                |Section    |
   |                    |                 |                |1.4.10,    |
   |                    |                 |                |Section    |
   |                    |                 |                |4.7.2,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.2.6      |
   +--------------------+-----------------+----------------+-----------+
   |acknowledged        |UTCDateTime      |Alert           |Section    |
   |                    |                 |                |4.5.2      |
   +--------------------+-----------------+----------------+-----------+
   |action              |String           |Alert           |Section    |
   |                    |                 |                |4.5.2      |
   +--------------------+-----------------+----------------+-----------+
   |alerts              |Id[Alert]        |Event, Task     |Section    |
   |                    |                 |                |4.5.2      |
   +--------------------+-----------------+----------------+-----------+
   |aliases             |String[Boolean]  |TimeZone        |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |byDay               |NDay[]           |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |byHour              |UnsignedInt[]    |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |byMinute            |UnsignedInt[]    |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |byMonth             |String[]         |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |byMonthDay          |Int[]            |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |bySecond            |UnsignedInt[]    |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |bySetPosition       |Int[]            |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |byWeekNo            |Int[]            |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |byYearDay           |Int[]            |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |categories          |String[Boolean]  |Event, Task,    |Section    |
   |                    |                 |Group           |4.2.10     |
   +--------------------+-----------------+----------------+-----------+
   |cid                 |String           |Link            |Section    |
   |                    |                 |                |1.4.11     |
   +--------------------+-----------------+----------------+-----------+
   |color               |String           |Event, Task,    |Section    |
   |                    |                 |Group           |4.2.11     |
   +--------------------+-----------------+----------------+-----------+
   |comments            |String[]         |TimeZoneRule    |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |contentType         |String           |Link            |Section    |
   |                    |                 |                |1.4.11     |
   +--------------------+-----------------+----------------+-----------+
   |coordinates         |String           |Location        |Section    |
   |                    |                 |                |4.2.5      |
   +--------------------+-----------------+----------------+-----------+
   |count               |UnsignedInt      |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |created             |UTCDateTime      |Event, Task,    |Section    |
   |                    |                 |Group           |4.1.5      |
   +--------------------+-----------------+----------------+-----------+
   |day                 |String           |NDay            |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |daylight            |TimeZoneRule[]   |TimeZone        |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |delegatedFrom       |Id[Boolean]      |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |delegatedTo         |Id[Boolean]      |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |description         |String           |Event, Task,    |Section    |
   |                    |                 |Location,       |4.2.2,     |
   |                    |                 |Participant,    |Section    |
   |                    |                 |VirtualLocation |4.2.5,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.4.6,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.2.6      |
   +--------------------+-----------------+----------------+-----------+
   |description         |String           |Event, Task     |Section    |
   |ContentType         |                 |                |4.2.3      |
   +--------------------+-----------------+----------------+-----------+
   |display             |String           |Link            |Section    |
   |                    |                 |                |1.4.11     |
   +--------------------+-----------------+----------------+-----------+
   |due                 |LocalDateTime    |Task            |Section    |
   |                    |                 |                |5.2.1      |
   +--------------------+-----------------+----------------+-----------+
   |duration            |Duration         |Event           |Section    |
   |                    |                 |                |5.1.2      |
   +--------------------+-----------------+----------------+-----------+
   |email               |String           |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |entries             |(Task|Event)[]   |Group           |Section    |
   |                    |                 |                |5.3.1      |
   +--------------------+-----------------+----------------+-----------+
   |estimatedDuration   |Duration         |Task            |Section    |
   |                    |                 |                |5.2.3      |
   +--------------------+-----------------+----------------+-----------+
   |excluded            |Boolean          |Event, Task     |Section    |
   |                    |                 |                |4.3.6      |
   +--------------------+-----------------+----------------+-----------+
   |excluded            |RecurrenceRule[] |Event, Task     |Section    |
   |RecurrenceRules     |                 |                |4.3.4      |
   +--------------------+-----------------+----------------+-----------+
   |expectReply         |Boolean          |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |features            |String[Boolean]  |VirtualLocation |Section    |
   |                    |                 |                |4.2.6      |
   +--------------------+-----------------+----------------+-----------+
   |firstDayOfWeek      |String           |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |freeBusyStatus      |String           |Event, Task     |Section    |
   |                    |                 |                |4.4.2      |
   +--------------------+-----------------+----------------+-----------+
   |frequency           |String           |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |href                |String           |Link            |Section    |
   |                    |                 |                |1.4.11     |
   +--------------------+-----------------+----------------+-----------+
   |interval            |UnsignedInt      |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |invitedBy           |Id               |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |keywords            |String[Boolean]  |Event, Task,    |Section    |
   |                    |                 |Group           |4.2.9      |
   +--------------------+-----------------+----------------+-----------+
   |kind                |String           |Participant     |Section    |
   |                    |                 |                |4.4.6      |

more rows coming up next part 🦋💜

okay bestie, the property index keeps going, and it's giving alphabetical chaos 🧚💜

   |language            |String           |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |links               |Id[Link]         |Group, Event,   |Section    |
   |                    |                 |Task, Location, |4.2.7,     |
   |                    |                 |Participant     |Section    |
   |                    |                 |                |4.2.5,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |locale              |String           |Group, Event,   |Section    |
   |                    |                 |Task            |4.2.8      |
   +--------------------+-----------------+----------------+-----------+
   |localizations       |String           |Event, Task     |Section    |
   |                    |[PatchObject]    |                |4.6.1      |
   +--------------------+-----------------+----------------+-----------+
   |locationId          |Id               |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |locations           |Id[Location]     |Event, Task     |Section    |
   |                    |                 |                |4.2.5      |
   +--------------------+-----------------+----------------+-----------+
   |locationTypes       |String[Boolean]  |Location        |Section    |
   |                    |                 |                |4.2.5      |
   +--------------------+-----------------+----------------+-----------+
   |memberOf            |Id[Boolean]      |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |method              |String           |Event, Task     |Section    |
   |                    |                 |                |4.1.8      |
   +--------------------+-----------------+----------------+-----------+
   |name                |String           |Location,       |Section    |
   |                    |                 |VirtualLocation,|4.2.5,     |
   |                    |                 |Participant     |Section    |
   |                    |                 |                |4.2.6,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |names               |String[Boolean]  |TimeZoneRule    |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |nthOfPeriod         |Int              |NDay            |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |offset              |SignedDuration   |OffsetTrigger   |Section    |
   |                    |                 |                |4.5.2      |
   +--------------------+-----------------+----------------+-----------+
   |offsetFrom          |UTCDateTime      |TimeZoneRule    |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |offsetTo            |UTCDateTime      |TimeZoneRule    |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |participants        |Id[Participant]  |Event, Task     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |participationComment|String           |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |participationStatus |String           |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |percentComplete     |UnsignedInt      |Task,           |Section    |
   |                    |                 |Participant     |5.2.4      |
   +--------------------+-----------------+----------------+-----------+
   |priority            |Int              |Event, Task     |Section    |
   |                    |                 |                |4.4.1      |
   +--------------------+-----------------+----------------+-----------+
   |privacy             |String           |Event, Task     |Section    |
   |                    |                 |                |4.4.3      |
   +--------------------+-----------------+----------------+-----------+
   |prodId              |String           |Event, Task,    |Section    |
   |                    |                 |Group           |4.1.4      |
   +--------------------+-----------------+----------------+-----------+
   |progress            |String           |Task,           |Section    |
   |                    |                 |Participant     |5.2.5      |
   +--------------------+-----------------+----------------+-----------+
   |progressUpdated     |UTCDateTime      |Task,           |Section    |
   |                    |                 |Participant     |5.2.6      |
   +--------------------+-----------------+----------------+-----------+
   |recurrenceId        |LocalDateTime    |Event, Task     |Section    |
   |                    |                 |                |4.3.1      |
   +--------------------+-----------------+----------------+-----------+
   |recurrenceIdTimeZone|TimeZoneId|null  |Event, Task     |Section    |
   |                    |                 |                |4.3.2      |
   +--------------------+-----------------+----------------+-----------+
   |recurrenceOverrides |LocalDateTime    |Event, Task,    |Section    |
   |                    |[PatchObject]    |TimeZoneRule    |4.3.5,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |recurrenceRules     |RecurrenceRule[] |Event, Task,    |Section    |
   |                    |                 |TimeZoneRule    |4.3.3,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |rel                 |String           |Link            |Section    |
   |                    |                 |                |1.4.11     |
   +--------------------+-----------------+----------------+-----------+
   |relatedTo           |String[Relation] |Event, Task,    |Section    |
   |                    |                 |Alert           |4.1.3,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.5.2      |
   +--------------------+-----------------+----------------+-----------+
   |relation            |String[Boolean]  |Relation        |Section    |
   |                    |                 |                |1.4.10     |
   +--------------------+-----------------+----------------+-----------+
   |relativeTo          |String           |OffsetTrigger,  |Section    |
   |                    |                 |Location        |4.5.2,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.2.5      |
   +--------------------+-----------------+----------------+-----------+
   |replyTo             |String[String]   |Event, Task     |Section    |
   |                    |                 |                |4.4.4      |
   +--------------------+-----------------+----------------+-----------+
   |requestStatus       |String           |Event, Task     |Section    |
   |                    |                 |                |4.4.7      |
   +--------------------+-----------------+----------------+-----------+
   |roles               |String[Boolean]  |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |rscale              |String           |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |sentBy              |String           |Event, Task,    |Section    |
   |                    |                 |Participant     |4.4.5,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |standard            |TimeZoneRule[]   |TimeZone        |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |start               |LocalDateTime    |TimeZoneRule    |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |scheduleAgent       |String           |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |scheduleForceSend   |Boolean          |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |scheduleSequence    |UnsignedInt      |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |scheduleStatus      |String[]         |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |scheduleUpdated     |UTCDateTime      |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |sendTo              |String[String]   |Participant     |Section    |
   |                    |                 |                |4.4.6      |
   +--------------------+-----------------+----------------+-----------+
   |sequence            |UnsignedInt      |Event, Task     |Section    |
   |                    |                 |                |4.1.7      |
   +--------------------+-----------------+----------------+-----------+
   |showWithoutTime     |Boolean          |Event, Task     |Section    |
   |                    |                 |                |4.2.4      |
   +--------------------+-----------------+----------------+-----------+
   |size                |UnsignedInt      |Link            |Section    |
   |                    |                 |                |1.4.11     |
   +--------------------+-----------------+----------------+-----------+
   |skip                |String           |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |source              |String           |Group           |Section    |
   |                    |                 |                |5.3.2      |
   +--------------------+-----------------+----------------+-----------+
   |start               |LocalDateTime    |Event, Task     |Section    |
   |                    |                 |                |5.1.1,     |
   |                    |                 |                |Section    |
   |                    |                 |                |5.2.2      |
   +--------------------+-----------------+----------------+-----------+
   |status              |String           |Event           |Section    |
   |                    |                 |                |5.1.3      |
   +--------------------+-----------------+----------------+-----------+
   |timeZone            |TimeZoneId|null  |Event, Task,    |Section    |
   |                    |                 |Location        |4.7.1,     |
   |                    |                 |                |Section    |
   |                    |                 |                |4.2.5      |
   +--------------------+-----------------+----------------+-----------+
   |timeZones           |TimeZoneId       |Event, Task     |Section    |
   |                    |[TimeZone]       |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |title               |String           |Event, Task,    |Section    |
   |                    |                 |Group, Link     |4.2.1      |
   +--------------------+-----------------+----------------+-----------+
   |trigger             |OffsetTrigger|   |Alert           |Section    |
   |                    |AbsoluteTrigger| |                |4.5.2      |
   |                    |UnknownTrigger   |                |           |
   +--------------------+-----------------+----------------+-----------+
   |tzId                |String           |TimeZone        |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |uid                 |String           |Event, Task,    |Section    |
   |                    |                 |Group           |4.1.2      |
   +--------------------+-----------------+----------------+-----------+
   |until               |LocalDateTime    |RecurrenceRule  |Section    |
   |                    |                 |                |4.3.3      |
   +--------------------+-----------------+----------------+-----------+
   |updated             |UTCDateTime      |Event, Task,    |Section    |
   |                    |                 |Group           |4.1.6      |
   +--------------------+-----------------+----------------+-----------+
   |uri                 |String           |VirtualLocation |Section    |
   |                    |                 |                |4.2.6      |
   +--------------------+-----------------+----------------+-----------+
   |url                 |String           |TimeZone        |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |useDefaultAlerts    |Boolean          |Event, Task     |Section    |
   |                    |                 |                |4.5.1      |
   +--------------------+-----------------+----------------+-----------+
   |validUntil          |UTCDateTime      |TimeZone        |Section    |
   |                    |                 |                |4.7.2      |
   +--------------------+-----------------+----------------+-----------+
   |virtualLocations    |Id               |Event, Task     |Section    |
   |                    |[VirtualLocation]|                |4.2.6      |
   +--------------------+-----------------+----------------+-----------+
   |when                |UTCDateTime      |AbsoluteTrigger |Section    |
   |                    |                 |                |4.5.2      |
   +--------------------+-----------------+----------------+-----------+

     Table 1: Initial Contents of the "JSCalendar Properties" Registry

8.3. Creation of the "JSCalendar Types" Registry ✨

okay so IANA made a brand new "JSCalendar Types" registry 🗂️💖 and the whole point is to dodge name collisions and have one complete reference for every data type used for JSCalendar property values 🦋. The way you register stuff here is literally the same as the "JSCalendar Properties" registry, which we already covered in Section 8.2 🎀.

8.3.1. "JSCalendar Types" Registry Template 🌸

Type Name: the name of the type 💅

Reference or Description: a brief description or RFC number and section reference where the Type is specified (may be omitted for "reserved" type names) 🫶

Intended Use: common, reserved, or obsolete ✨

Change Controller: who may request a change to this entry's definition ("IETF" for RFCs from the IETF stream) 👑

8.3.2. Initial Contents for the "JSCalendar Types" Registry 🍓

okay here's the starter pack 🧚 All of these properties are for common use, every RFC section reference points back to this document, and the change controller for all of them is "IETF" 💜

   +=================+==========================+
   | Type Name       | Reference or Description |
   +=================+==========================+
   | Alert           | Section 4.5.2            |
   +-----------------+--------------------------+
   | Boolean         | Section 1.3              |
   +-----------------+--------------------------+
   | Duration        | Section 1.4.6            |
   +-----------------+--------------------------+
   | Id              | Section 1.4.1            |
   +-----------------+--------------------------+
   | Int             | Section 1.4.2            |
   +-----------------+--------------------------+
   | LocalDateTime   | Section 1.4.5            |
   +-----------------+--------------------------+
   | Link            | Section 1.4.11           |
   +-----------------+--------------------------+
   | Location        | Section 4.2.5            |
   +-----------------+--------------------------+
   | NDay            | Section 4.3.3            |
   +-----------------+--------------------------+
   | Number          | Section 1.3              |
   +-----------------+--------------------------+
   | Participant     | Section 4.4.6            |
   +-----------------+--------------------------+
   | PatchObject     | Section 1.4.9            |
   +-----------------+--------------------------+
   | RecurrenceRule  | Section 4.3.3            |
   +-----------------+--------------------------+
   | Relation        | Section 1.4.10           |
   +-----------------+--------------------------+
   | SignedDuration  | Section 1.4.7            |
   +-----------------+--------------------------+
   | String          | Section 1.3              |
   +-----------------+--------------------------+
   | TimeZone        | Section 4.7.2            |
   +-----------------+--------------------------+
   | TimeZoneId      | Section 1.4.8            |
   +-----------------+--------------------------+
   | TimeZoneRule    | Section 4.7.2            |
   +-----------------+--------------------------+
   | UnsignedInt     | Section 1.4.3            |
   +-----------------+--------------------------+
   | UTCDateTime     | Section 1.4.4            |
   +-----------------+--------------------------+
   | VirtualLocation | Section 4.2.6            |
   +-----------------+--------------------------+

          Table 2: Initial Contents of the
            "JSCalendar Types" Registry

8.4. Creation of the "JSCalendar Enum Values" Registry 🌈

IANA made the "JSCalendar Enum Values" registry so that semantics for properties with enumerable values can be extended in an interoperable way 🔥. Each of those properties gets its own subregistry of allowed values 💖. Registering a new enum value, or adding a new enumerable property, follows the same process as the "JSCalendar Properties" registry, as defined in Section 8.2 ✨.

8.4.1. "JSCalendar Enum Values" Registry Property Template 🦋

this template is for adding a subregistry for a new enumerable property to the "JSCalendar Enum" registry 🎀

Property Name: these are the name(s) of the property or properties where these values may be used. This MUST be registered in the "JSCalendar Properties" registry. 🫶

Context: this is the list of allowed object types where the property or properties may appear, as registered in the "JSCalendar Properties" registry. This disambiguates where there may be two distinct properties with the same name in different contexts. 🧚

Change Controller: ("IETF" for properties defined in RFCs from the IETF stream). 👑

Initial Contents: this is the initial list of defined values for this enum, using the template defined in Section 8.4.2. A subregistry will be created with these values for this property name/context tuple. 🍓

8.4.2. "JSCalendar Enum Values" Registry Value Template 💜

this template is for adding a new enum value to a subregistry in the JSCalendar Enum registry 🌸

Enum Value: the verbatim value of the enum 💅

Reference or Description: a brief description or RFC number and section reference for the semantics of this value ✨

8.4.3. Initial Contents for the "JSCalendar Enum Values" Registry 💖

for each subregistry created in this section, all RFC section references point to this document 🙈

   Property Name:      action
   Context:            Alert
   Change Controller:  IETF
   Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | display    | Section 4.5.2            |
                       +------------+--------------------------+
                       | email      | Section 4.5.2            |
                       +------------+--------------------------+

                          Table 3: JSCalendar Enum Values for
                                action (Context: Alert)

   Property Name:      display
   Context:            Link
   Change Controller:  IETF
   Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | badge      | Section 1.4.11           |
                       +------------+--------------------------+
                       | graphic    | Section 1.4.11           |
                       +------------+--------------------------+
                       | fullsize   | Section 1.4.11           |
                       +------------+--------------------------+
                       | thumbnail  | Section 1.4.11           |
                       +------------+--------------------------+

                          Table 4: JSCalendar Enum Values for
                                display (Context: Link)

9. References 📚

Okay so the enum tables are literally the best part of the spec, and we're wrapping them up here 💅

  • Property Name: features
  • Context: VirtualLocation
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | audio      | Section 4.2.6            |
                       +------------+--------------------------+
                       | chat       | Section 4.2.6            |
                       +------------+--------------------------+
                       | feed       | Section 4.2.6            |
                       +------------+--------------------------+
                       | moderator  | Section 4.2.6            |
                       +------------+--------------------------+
                       | phone      | Section 4.2.6            |
                       +------------+--------------------------+
                       | screen     | Section 4.2.6            |
                       +------------+--------------------------+
                       | video      | Section 4.2.6            |
                       +------------+--------------------------+

                          Table 5: JSCalendar Enum Values for
                          features (Context: VirtualLocation)
  • Property Name: freeBusyStatus
  • Context: Event, Task
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | free       | Section 4.4.2            |
                       +------------+--------------------------+
                       | busy       | Section 4.4.2            |
                       +------------+--------------------------+

                          Table 6: JSCalendar Enum Values for
                         freeBusyStatus (Context: Event, Task)
  • Property Name: kind
  • Context: Participant
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | individual | Section 4.4.6            |
                       +------------+--------------------------+
                       | group      | Section 4.4.6            |
                       +------------+--------------------------+
                       | resource   | Section 4.4.6            |
                       +------------+--------------------------+
                       | location   | Section 4.4.6            |
                       +------------+--------------------------+

                          Table 7: JSCalendar Enum Values for
                              kind (Context: Participant)
  • Property Name: participationStatus
  • Context: Participant
  • Change Controller: IETF
  • Initial Contents:
                       +==============+==========================+
                       | Enum Value   | Reference or Description |
                       +==============+==========================+
                       | needs-action | Section 4.4.6            |
                       +--------------+--------------------------+
                       | accepted     | Section 4.4.6            |
                       +--------------+--------------------------+
                       | declined     | Section 4.4.6            |
                       +--------------+--------------------------+
                       | tentative    | Section 4.4.6            |
                       +--------------+--------------------------+
                       | delegated    | Section 4.4.6            |
                       +--------------+--------------------------+

                           Table 8: JSCalendar Enum Values for
                              participationStatus (Context:
                                       Participant)
  • Property Name: privacy
  • Context: Event, Task
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | public     | Section 4.4.3            |
                       +------------+--------------------------+
                       | private    | Section 4.4.3            |
                       +------------+--------------------------+
                       | secret     | Section 4.4.3            |
                       +------------+--------------------------+

                          Table 9: JSCalendar Enum Values for
                             privacy (Context: Event, Task)
  • Property Name: progress
  • Context: Task, Participant
  • Change Controller: IETF
  • Initial Contents:
                       +==============+==========================+
                       | Enum Value   | Reference or Description |
                       +==============+==========================+
                       | needs-action | Section 5.2.5            |
                       +--------------+--------------------------+
                       | in-process   | Section 5.2.5            |
                       +--------------+--------------------------+
                       | completed    | Section 5.2.5            |
                       +--------------+--------------------------+
                       | failed       | Section 5.2.5            |
                       +--------------+--------------------------+
                       | cancelled    | Section 5.2.5            |
                       +--------------+--------------------------+

                           Table 10: JSCalendar Enum Values for
                          progress (Context: Task, Participant)
  • Property Name: relation
  • Context: Relation
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | first      | Section 1.4.10           |
                       +------------+--------------------------+
                       | next       | Section 1.4.10           |
                       +------------+--------------------------+
                       | child      | Section 1.4.10           |
                       +------------+--------------------------+
                       | parent     | Section 1.4.10           |
                       +------------+--------------------------+

                          Table 11: JSCalendar Enum Values for
                              relation (Context: Relation)
  • Property Name: relativeTo
  • Context: OffsetTrigger, Location
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | start      | Section 4.5.2            |
                       +------------+--------------------------+
                       | end        | Section 4.5.2            |
                       +------------+--------------------------+

                          Table 12: JSCalendar Enum Values for
                          relativeTo (Context: OffsetTrigger,
                                       Location)
  • Property Name: roles
  • Context: Participant
  • Change Controller: IETF
  • Initial Contents:
                       +===============+==========================+
                       | Enum Value    | Reference or Description |
                       +===============+==========================+
                       | owner         | Section 4.4.6            |
                       +---------------+--------------------------+
                       | attendee      | Section 4.4.6            |
                       +---------------+--------------------------+
                       | optional      | Section 4.4.6            |
                       +---------------+--------------------------+
                       | informational | Section 4.4.6            |
                       +---------------+--------------------------+
                       | chair         | Section 4.4.6            |
                       +---------------+--------------------------+
                       | contact       | Section 4.4.6            |
                       +---------------+--------------------------+

                           Table 13: JSCalendar Enum Values for
                               roles (Context: Participant)
  • Property Name: scheduleAgent
  • Context: Participant
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | server     | Section 4.4.6            |
                       +------------+--------------------------+
                       | client     | Section 4.4.6            |
                       +------------+--------------------------+
                       | none       | Section 4.4.6            |
                       +------------+--------------------------+

                          Table 14: JSCalendar Enum Values for
                          scheduleAgent (Context: Participant)
  • Property Name: status
  • Context: Event
  • Change Controller: IETF
  • Initial Contents:
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | confirmed  | Section 5.1.3            |
                       +------------+--------------------------+
                       | cancelled  | Section 5.1.3            |
                       +------------+--------------------------+
                       | tentative  | Section 5.1.3            |
                       +------------+--------------------------+

                          Table 15: JSCalendar Enum Values for
                                status (Context: Event)

9.1. Normative References ✨

9.2. Informative References 🦋

Acknowledgments 💖

The authors wanted to give a huge shoutout to the members of CalConnect 🫶 for their valuable contributions! This spec actually started out as the work of the API technical committee of CalConnect: The Calendaring and Scheduling Consortium. Iconic teamwork, honestly 👑.

Authors' Addresses 🎀

   Neil Jenkins
   Fastmail
   Collins St. West
   P.O. Box 234
   Melbourne  VIC 8007
   Australia

   Email: neilj@fastmailteam.com
   URI:   https://www.fastmail.com


   Robert Stepanek
   Fastmail
   Collins St. West
   P.O. Box 234
   Melbourne  VIC 8007
   Australia

   Email: rsto@fastmailteam.com
   URI:   https://www.fastmail.com
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