Sat, 19 Dec 2009
Updated Tibetan Calendar
I've updated the Tibetan calendar on my downloads page. The update consists of adding more data to the calendar. Previously it only went to 2010, but now it goes to 2020. The most notable feature of the Tibetan calendar is how dates are skipped or repeated. For example, a month might have two 14th days and no 22nd. In the Tibetan calendar the month is divided into 30 "lunar days," which are each 12 degrees in the 360 degrees of the lunar orbit. The new moon is the 30th lunar day and the full moon is the 15th. The day of the month in the Tibetan calendar is whatever the lunar day is at one hour before sunrise. Because the moon's motion is irregular, sometimes faster or slower, the Tibetan calendar has skipped and repeated days.
The calculation of these dates is complicated and my calendar program doesn't do the calculations itself. Instead, my script has the start date of each month and a list of skipped and repeated sites. The data is exteacted from the calendars at Ed Henning's Kalachakra Calendar site using a short Perl script that I wrote.
