yabc – Yet Another Bedside Clock. This is a clock app that is designed to be run at the bedside or near a star map. It will display the time without turning off until the battery percentage drops below a user specified value. There are ten predefined, and one user defined display configurations. A single tap of the moon and star icon will bring up a red tinted clock showing the local sidereal time. In settings, you can add a moon display, change colors, and configure the user defined clock display.

Clock Times:

GMT – Greenwich Mean Time

GMST – Greenwich Mean Sidereal Time

Julian Date – Seconds since noon 1st January 4713 B.C.

LMST – Local Mean Sidereal Time

Modified Julian Date – Julian Date – 2400000.5

Predefined displays:

– Desk Clock – Day, Time, Date

– ISO 8901 – yyyy-mm-ssThh:mm:ss+tz

– ISO 8901 GMT – yyyy-mm-ssThh:mm:ssZ

– Greenwich Mean Sidereal Time – ‘HH’h ‘mm’s ‘ss’

– Julian – day.time in seconds since noon 1st January 4713 B.C.

– Local Mean Sidereal Time – ‘HH’h ‘mm’ **

– System Default – based on your iOS settings

– Time HH:MM:SS, Month, Day

– Time HH:MM

– Time HH:MM:SS, Day, Month, Year

– User Defined – you pick the format!

**Note: if you select Local Sidereal Mean Time display, you’ll also need to enable the setting to allow access to your location information. I only need your longitude for the calculations.