Understanding the calendar
What is Sankranti?
If you arrived here looking for Makar Sankranti, you are seeing one part of a much larger cycle. Sankranti means a passage or transition. In the Hindu calendrical tradition, it is the exact instant the Sun moves into a new sidereal zodiac sign.
The Sun crosses 12 sign boundaries during its annual journey, so there are 12 Sankrantis. Each transition begins a new solar month. That is why Sankranti dates matter in solar calendars followed in Tamil Nadu, Kerala, Bengal, Odisha, Assam and other regions.
Makar Sankranti became the most widely celebrated because it brings together Uttarayana, harvest customs, sacred bathing, charity and many regional festivals. Still, Makara is one transition among 12. Mesha, Karka, Tula and the others belong to the same complete system.