Astral.js is a Javascript library that makes it easy to:
Astral.js is an implementation in Javascript of some of the algorithms in
Jean Meeus "Astronomical Algorithms"
Willmann-Bell, Inc.
2nd edition (1998 with corrections as of June 15, 2005);
ISBN: 0-943396-61-1
as used in the book
Nachum Dershowitz, Edward M. Reingold "Calendrical Calculations"
Cambridge University Press; 3rd edition (December 10, 2007)
Paperback; ISBN-13: 9780521702386
E. M. Reingold and N. Dershowitz,
3rd ed., Cambridge University Press, 2008.
not even beta but porting from PyCalCal which is instead pretty well tested and usable.
I want to thank: