In Bangladesh, Tagore’s Birthday is an official holiday. Back in 2003 I wondered why this day is not always corresponding with our Western counting, as it was celebrated on 9 May. It appeared that also 7 or 8 May may occur.
The reason is that according to the Bangla calendar Tagore was born on 25 Boishakh 1268. This corresponds with 7 May 1861 on the Western calendar. As these calendars are not fully exchangeable, little defection from the Western counting may occur. And so, in 2013 Tagore’s birthday is celebrated on 8 May.
The twelve months are based on the names of the nokkhotro (lunar mansions), when a particular star or constellation dominates the lunar cycle. The year starts with the month Boishakh, and corresponds with April/May. It is named after the constellation Bishakha, 1), which are the stars α-, β-, and γ-Libra.
(an earlier version of this blogpost was published on 14 May 2003 in Lindosblog)
1. Wikipedia: Bengali calendar