Calendrical calculations

the long version

"A valuable resource for working programmers, as well as a fount of useful algorithmic tools for computer scientists, this new edition of the popular calendars book expands the treatment of the previous edition to new calendar variants: generic cyclical calendars and astronomical lunar calendars as well as the Korean, Vietnamese, Aztec, and Tibetan calendars. The authors frame the calendars of the world in a completely algorithmic form, allowing easy conversion among these calendars and the determination of secular and religious holidays. LISP and Java code for all the algorithms are available on the Web."--Publisher's description.