Malayalam calendar

The Malayalam calendar, Kerala's Kolla varsham, is a solar calendar. A month is the time the Sun spends in one sidereal sign: Chingam while it is in Simha (Leo), Kanni in Kanya, and so on to Karkidakam in Karka (Cancer). The months have 29 to 32 days and begin around the middle of the Gregorian month.

Which day is the first of a month follows the Kerala rule: divide the daylight, from sunrise to sunset, into five equal parts. If the Sun enters the new sign (the sankramam) within the first three — by the end of madhyahna — the month begins that day; if it enters later in the afternoon, in the evening or at night, the next day. An entry after midnight but before sunrise belongs to the night before, so the month begins on that calendar date. This differs from the Tamil rule, which keeps a sankramam of the late afternoon on the same day.

The Kollam era begins with Chingam: Chingam 1 is the Malayalam New Year, and the year number is the Common Era year minus 824 from Chingam to December, minus 825 from January to Karkidakam. Vishu, on the other hand, is kept on the first sunrise after the Sun enters Mesha (Aries), when the Vishukkani is seen at dawn — so in some years Vishu is Medam 2, not Medam 1.

Days are known by their nakshatra (naal) more than by their tithi, and Kerala's festivals follow it: Onam is Thiruvonam in Chingam, Thrissur Pooram the Pooram of Medam, Attukal Pongala the Pooram of Kumbham, Thiruvathira the Thiruvathira of Dhanu. Others are fixed by the solar month itself: the Mandala season runs 41 days from Vrischikam 1, Karkidaka Vavu is the new moon of Karkidakam.

Our dates are computed for Thiruvananthapuram. The sankramam moments we compute can be a few minutes earlier than those of printed almanacs; when a sankramam falls within minutes of the madhyahna cut-off, a month can begin a day apart from your almanac. Temples announce their own festival days (Thrissur, Attukal, Sabarimala); when they differ, follow the temple.