Tula Sankranti 2009: Pomona, California

Tula Sankranti marks the Sun's transit into Libra and is a Vishuva Sankranti -- day and night are again of equal length, the autumnal counterpart to Mesha Sankranti's spring equinox.

The exact moment the Sun crosses into Tula (Libra) is called the Sankranti. The Punyakala is the auspicious window around that moment -- its exact length and placement (before or after the Sankranti, and how it is measured) follows a traditional rule that depends on which of the twelve Sankrantis this is; Karka and Makara Sankranti (the two Ayana Sankrantis, marking the start of Dakshinayana and Uttarayana) each have their own distinct rule, and the Vishuva (Mesha/Tula), Vishnupadi, and Shadshitimukhi Sankrantis each follow one of three other rules. Charity (daan), holy baths, and worship performed during the Punyakala window are traditionally held to be especially meritorious.