Meena Sankranti marks the Sun's passage into Meena, the twelfth and final sign of the sidereal zodiac, corresponding to Pisces. It is determined by the Sun reaching a longitude of three hundred and thirty degrees against the fixed stars, using the Lahiri ayanamsa, and normally falls in mid-March.
Like the other sankrantis it is a solar event, set by the Sun's ecliptic longitude and not by any lunar day or phase, which is what separates it from festivals fixed to the lunar month. The transit instant is converted to local time, so the observed date and the timing of ritual bathing or giving can vary by a day between cities.
The month that begins here closes the solar year, which turns over at Mesha Sankranti about thirty days later. In Odisha the fortnight around it is kept as Meena Sankranti or Phagu Dasami with fairs at Shiva temples, and in the Tamil calendar it opens the month of Panguni.