SUNDAZEL(1)

✨ NAME ✨

okay so sundazel — section 1, User Commands, bestie — is here to compute the time of Solar passage. That's the whole vibe.

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🌸 SYNOPSIS 🌸

sundazel [<option>] [<yyyymmdd>]

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💫 DESCRIPTION 💫

sundazel computes the local time of the Sun's passage through the specified apparent longitude or latitude in a user-defined coordinate system, for the specified location on the specified date (default today). yes, today is the default, we love a low-effort queen 💖

It also prints the Sun's apparent hour angle, azimuth, elevation, and the longitude and latitude in user coordinates — all in degrees. Refraction is accounted for, periodt.

You can also use sundazel to compute the time of sunrise and set, the Sun's right ascension and declination, and the Equation of Time. versatile icon behavior ✨

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👑 OPTIONS 👑

• -p <option> — this is where you tell sundazel the Solar passage you want and, if relevant, the coordinate value in degrees. The choices are:
  • sunrise — Sunrise. the morning moment ☀️
  • sunset — Sunset. the evening glow 🌅
  • lng=<lng> — Longitude of the Sun in the user-defined coordinate system.
  • lat=<lat> — Latitude of the Sun in the user-defined coordinate system.
• -l <lng>,<lat> — Longitude and latitude of the observer. where you're standing, bestie 🌍
• -t <tz> — The observer's time zone, positive east of Greenwich (hr). hours, east-positive, no cap ⏰
• -u <az>,<el>,<zlng> — Azimuth and elevation of the pole of the user-defined coordinate system, and the longitude of the zenith (deg). See below for the tea 🫖
• -n — Set the user-defined coordinate system as one with pole due north on the horizon, with zero of longitude at the zenith. north pole energy 🧭
• -w — Set the user-defined coordinate system as one with pole due west on the horizon, with zero of longitude at the zenith. west pole energy 🌇
• -v — Also print the Sun's right ascension, declination (deg), and the Equation of Time (min). extra data? we love extra data 📈

The user-defined coordinate system is a right-handed spherical coordinate system with its pole at the specified azimuth and elevation, and with zenith having the specified longitude. If omitted, the default is a right-handed system with its pole at the zenith and prime meridian due north, i.e. similar to azimuth and elevation except that longitude increases in the reverse sense to azimuth, i.e. from north through west rather than north through east. iykyk 💅

Setting a range of azimuth or elevation often provides a poor criterion for timing the passage of the Sun, for example in determining when it shines directly through a skylight, or when an awning casts a shadow on a particular point on the ground. In such cases the projection of the skylight or awning from the ground onto the sky should be considered. Some other coordinate system may provide a better fit to the region of the sky thereby defined. For example, the passage of the Sun across a skylight oriented at azimuth alpha might be handled via a coordinate system with pole on the horizon at that azimuth and considering the Sun's passage through a range of longitude in this system. Perhaps better might be to use a coordinate system with pole at alpha-90 and considering a range of latitude. geometry side quest, but make it fashion 🦋

Sunrise and sunset correspond to first/last contact of the Sun's limb on the horizon, corresponding to apparent elevation -0.27 deg (true elevation -0.79 deg). If no options are specified, the default is to calculate the time of sunset. If more than one p option is specified, only the last is effective. important!! the last -p wins, so don't be messy with duplicates. 💀

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And that's the whole manual page, bestie. This masterpiece is from sundazel 8.9, dated June 2026. slay, hydrate, and may your Sun passages always be accurately timed 💖✨🎀