Good morning. It's almost twenty to eleven. (Japan Standard Time)

calendar

Here are C codes translated by me. The original Common Lisp code is from ``Calendrical Calculations'' and ``Calendrical Calculations, II: Three Historical Calendars''.

Nachum Dershowitz and Edward M. Reingold, ``Calendrical Calculations'' Software---Practice & Experience, vol. 20, no. 9 (September, 1990), pp. 899--928
Edward M. Reingold, Nachum Dershowitz and Stewart M. Clamen, ``Calendrical Calculations, II: Three Historical Calendars'' Software---Practice & Experience, vol. 23, no. 4 (April, 1993), pp. 383--404

In addition to the above, I also wrote code for a few calendars (I can't assure you that they're right).

This package also includes three independent modules for Python and Ruby.

A "Calendar" module

This is a "Calendrical Calculations" module.

This module supports the following calendars:

Gregorian (current civil), Calendar week (ISO), Julian (old civil), Islamic (Moslem), Hebrew (Jewish), Mayan, French Revolutionary, Old Hindu, Achelis', Coptic, Ethiopian, Jalaali (incomplete), Kyureki (Japanese traditional with CE)

NOTE: This module now handles jd and mjd based on "chronological" sense.