tweaks the Gregorian module. Coptic The Coptic calendar is by some sources ("St. Marks' Coptic Orthodox Church" web pages) is for now on in sync with the Gregorian Calendar, so this module too inherits and tweaks the Gregorian module. It needs to be adjusted for historical use. Julian This is the Julian calendar, with the small changes to the Gregorian calendar (leap years).
The Badi calendar used by the Baha'i religion is based on the
solar year. For the time being it is in sync with the Gregorian
Islamic This is the Islamic calendar, using the 'Calendrical Calculations' rules for new moon. It is based directly on the YMD module. Stardate This is the (TNG) Stardate calendar, which consists of one time unit only, the Tick (1000 Tick is one earth year). It is based directly on TimeRanges.