t.shift(1grass)

📦
version 8.5.0 · 10 versions
, in alpine 3.24, ubuntu stonking

✨ t.shift — shifting your space time dataset's whole vibe 💅

okay so bestie, this is the GRASS User's Manual page for t.shift(1grass) and I'm gonna hold your hand through it, no cap 💖

🏷️ NAME

t.shift — shifts temporally the maps of a space time dataset. yes, literally moving time. main character behavior honestly ⏳

🔑 KEYWORDS

temporal, time management, shift, time

📜 SYNOPSIS

t.shift
t.shift --help
t.shift input=name  [type=name]  granularity=string  [--help]
[--verbose]  [--quiet]  [--ui]

🚩 Flags

  • --help — Print usage summary (the classic "help me bestie" move)
  • --verbose — Verbose module output (she's chatty, we love that)
  • --quiet — Quiet module output (she's giving mysterious 🫶)
  • --ui — Force launching GUI dialog

🎀 Parameters

  • input=name [required] — Name of an existing space time dataset
  • type=name — Type of the input space time dataset
    • Options: strds, stvds, str3ds
    • Default: strds
  • granularity=string [required] — Shift granularity
    • Format absolute time: "x years, x months, x weeks, x days, x hours, x minutes, x seconds", relative time is of type integer

🌸 DESCRIPTION

t.shift is designed to temporally shift all registered maps in a space time dataset with a user defined granularity. Raster, 3D raster and vector space time datasets are supported. like... all of them. inclusive queen 👑

The format of the absolute time granularity is "number unit". Number is an integer, unit is the temporal unit that can be one of year(s), month(s), week(s), day(s), hour(s), minute(s) or second(s). pick your fighter 🥊

The granularity in case of relative time is an integer. The temporal unit is the unit of the space time dataset and can not be modified. she's locked in fr fr 🔒

⚠️ NOTES

Be careful when shifting space time datasets with absolute time. This is the part where you pay attention, bestie 👀

The temporal granularity may change if you shift a space time dataset with a unit that is different from the space time dataset granularity. Be aware that the shifting with months and years may result in incorrect days per month. Shifting the date 20012-03-31 with a granularity of one month will result in 2012-04-31 which is incorrect. In this case an error will raise and the shifting will not performed for the whole dataset. 💀 yeah that's a whole mess, don't do that

You can use the extraction module to shift only a subset of maps from a space time dataset. Be aware that the shifting of maps affect all space time datasets in which they are registered. it's giving ripple effect, it's giving consequences 🦋

🧪 EXAMPLE

We create 6 raster maps and register them in a space time raster dataset using an increment of one day. Then we shift the time intervals with a granularity of 12 hours. let's gooo ✨

r.mapcalc expression="prec_1 = rand(0, 550)"
r.mapcalc expression="prec_2 = rand(0, 450)"
r.mapcalc expression="prec_3 = rand(0, 320)"
r.mapcalc expression="prec_4 = rand(0, 510)"
r.mapcalc expression="prec_5 = rand(0, 300)"
r.mapcalc expression="prec_6 = rand(0, 650)"
t.create type=strds temporaltype=absolute \
         output=precipitation_daily \
         title="Daily precipitation" \
         description="Test dataset with daily precipitation"
t.register -i type=raster input=precipitation_daily \
           maps=prec_1,prec_2,prec_3,prec_4,prec_5,prec_6 \
           start=2012-01-01 increment="1 day"
t.info type=strds input=precipitation_daily

and then t.info spills all the tea, look at this 💅

 +-------------------- Space Time Raster Dataset -----------------------------+
 |                                                                            |
 +-------------------- Basic information -------------------------------------+
 | Id: ........................ precipitation_daily@PERMANENT
 | Name: ...................... precipitation_daily
 | Mapset: .................... PERMANENT
 | Creator: ................... soeren
 | Temporal type: ............. absolute
 | Creation time: ............. 2014-11-23 19:20:26.004855
 | Modification time:.......... 2014-11-23 19:20:26.471536
 | Semantic type:.............. mean
 +-------------------- Absolute time -----------------------------------------+
 | Start time:................. 2012-01-01 00:00:00
 | End time:................... 2012-01-07 00:00:00
 | Granularity:................ 1 day
 | Temporal type of maps:...... interval
 +-------------------- Spatial extent ----------------------------------------+
 | North:...................... 80.0
 | South:...................... 0.0
 | East:.. .................... 120.0
 | West:....................... 0.0
 | Top:........................ 0.0
 | Bottom:..................... 0.0
 +-------------------- Metadata information ----------------------------------+
 | Raster register table:...... raster_map_register_882043e9afaa4e60b845aceb1a1fee2c
 | North-South resolution min:. 10.0
 | North-South resolution max:. 10.0
 | East-west resolution min:... 10.0
 | East-west resolution max:... 10.0
 | Minimum value min:.......... 0.0
 | Minimum value max:.......... 16.0
 | Maximum value min:.......... 297.0
 | Maximum value max:.......... 647.0
 | Aggregation type:........... None
 | Number of registered maps:.. 6
 |
 | Title:
 | Daily precipitation
 | Description:
 | Test dataset with daily precipitation
 | Command history:
 | # 2014-11-23 19:20:26
 | t.create type="strds" temporaltype="absolute"
 |     output="precipitation_daily" title="Daily precipitation"
 |     description="Test dataset with daily precipitation"
 | # 2014-11-23 19:20:26
 | t.register -i type="rast" input="precipitation_daily"
 |     maps="prec_1,prec_2,prec_3,prec_4,prec_5,prec_6" start="2012-01-01"
 |     increment="1 day"
 |
 +----------------------------------------------------------------------------+

then we peek at the list 🍓

t.rast.list input=precipitation_daily
name|mapset|start_time|end_time
prec_1|PERMANENT|2012-01-01 00:00:00|2012-01-02 00:00:00
prec_2|PERMANENT|2012-01-02 00:00:00|2012-01-03 00:00:00
prec_3|PERMANENT|2012-01-03 00:00:00|2012-01-04 00:00:00
prec_4|PERMANENT|2012-01-04 00:00:00|2012-01-05 00:00:00
prec_5|PERMANENT|2012-01-05 00:00:00|2012-01-06 00:00:00
prec_6|PERMANENT|2012-01-06 00:00:00|2012-01-07 00:00:00

and NOW the moment you've all been waiting for, the shift ✨

t.shift type=strds input=precipitation_daily granularity="12 hours"
t.info type=strds input=precipitation_daily
 +-------------------- Space Time Raster Dataset -----------------------------+
 |                                                                            |
 +-------------------- Basic information -------------------------------------+
 | Id: ........................ precipitation_daily@PERMANENT
 | Name: ...................... precipitation_daily
 | Mapset: .................... PERMANENT
 | Creator: ................... soeren
 | Temporal type: ............. absolute
 | Creation time: ............. 2014-11-23 19:20:26.004855
 | Modification time:.......... 2014-11-23 19:21:08.240018
 | Semantic type:.............. mean
 +-------------------- Absolute time -----------------------------------------+
 | Start time:................. 2012-01-01 12:00:00
 | End time:................... 2012-01-07 12:00:00
 | Granularity:................ 24 hours
 | Temporal type of maps:...... interval
 +-------------------- Spatial extent ----------------------------------------+
 | North:...................... 80.0
 | South:...................... 0.0
 | East:.. .................... 120.0
 | West:....................... 0.0
 | Top:........................ 0.0
 | Bottom:..................... 0.0
 +-------------------- Metadata information ----------------------------------+
 | Raster register table:...... raster_map_register_882043e9afaa4e60b845aceb1a1fee2c
 | North-South resolution min:. 10.0
 | North-South resolution max:. 10.0
 | East-west resolution min:... 10.0
 | East-west resolution max:... 10.0
 | Minimum value min:.......... 0.0
 | Minimum value max:.......... 16.0
 | Maximum value min:.......... 297.0
 | Maximum value max:.......... 647.0
 | Aggregation type:........... None
 | Number of registered maps:.. 6
 |
 | Title:
 | Daily precipitation
 | Description:
 | Test dataset with daily precipitation
 | Command history:
 | # 2014-11-23 19:20:26
 | t.create type="strds" temporaltype="absolute"
 |     output="precipitation_daily" title="Daily precipitation"
 |     description="Test dataset with daily precipitation"
 | # 2014-11-23 19:20:26
 | t.register -i type="rast" input="precipitation_daily"
 |     maps="prec_1,prec_2,prec_3,prec_4,prec_5,prec_6" start="2012-01-01"
 |     increment="1 day"
 | # 2014-11-23 19:21:08
 | t.shift type="strds" input="precipitation_daily"
 |     granularity="12 hours"
 |
 +----------------------------------------------------------------------------+

and boom, look at those new times 😭👑

t.rast.list input=precipitation_daily
name|mapset|start_time|end_time
prec_1|PERMANENT|2012-01-01 12:00:00|2012-01-02 12:00:00
prec_2|PERMANENT|2012-01-02 12:00:00|2012-01-03 12:00:00
prec_3|PERMANENT|2012-01-03 12:00:00|2012-01-04 12:00:00
prec_4|PERMANENT|2012-01-04 12:00:00|2012-01-05 12:00:00
prec_5|PERMANENT|2012-01-05 12:00:00|2012-01-06 12:00:00
prec_6|PERMANENT|2012-01-06 12:00:00|2012-01-07 12:00:00

ate. no crumbs. 🍽️💖

👀 SEE ALSO

t.create, t.register, t.snap

🫶 AUTHOR

Sören Gebbert, Thünen Institute of Climate-Smart Agriculture — thank you for your service king 🎀

💻 SOURCE CODE

Available at: t.shift source code (history)

Latest change: Thursday Dec 18 07:11:47 2025 in commit: cf870a5e49fd2643a55de543467edf5c2e61d640

Main index | Temporal index | Topics index | Keywords index | Graphical index | Full index

okay so that's the whole page bestie, you're fully caught up 💜 and like a lil sign-off moment: this is GRASS 8.5.0, © 2003-2026 GRASS Development Team, from the GRASS 8.5.0 Reference Manual, and yes t.shift(1grass) is the manual name up top. slay, go shift some time ✨🦋🌸

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