Vishudnam Although the list of months starts with Leo (close to the main festival Onam), the more traditional date for the start of the New Year is the first of Medam (the festival of Vishu). The word Vishu means `equal’ in Sanskrit; Vishudinam means equinox 6. So one might be tempted identify this festival with the spring equinox. But if that is the case, the calendar is off by 25 days. The spring equinox is on March 20 and Vishu was celebrated this year on April 15th. This does not mean that the Kollam calendar itself is inaccurate. Perhaps the early custom was for Vishu to coincide with the equinox. After it got out of sync, a corrected calendar could have been developed in which the error did not grow anymore. It would take much greater political will to lop off three weeks from a widely used civil calendar, so probably that was not done. Further study is needed to know what really happened here. Recall that when the Gregorian calendar was instituted, even with the support of a Papal Bull, there were many protests 7 over eleven days that had to cut out of the calendar. http://sgrajeev.com/the-almanack/