Makar Sankranti

The Sun's entry into Makara, marking the start of Uttarayana. Kept as Pongal in Tamil Nadu, Magh Bihu in Assam, Maghi in Punjab and Uttarayan in Gujarat.

This is a solar festival, not a lunar one — which is why it barely moves in the Gregorian calendar while Diwali swings by a month. It is fixed by the moment the Sun enters Makara rashi. When that moment falls after sunset the observance rolls to the next day, which is why 2023 was kept on 15 January although the ingress was on the 14th.

• Ingress computed by panchang-core; the after-sunset roll is the standard drik rule.