Regional Indian Calendars Compared: Tamil, Malayalam, Bengali, Assamese, Odia & Nepali
A comprehensive deep-dive into regional solar transits (Sankranti) and localized era reckonings.
By Regional Cultural Research · Updated August 2026
India boasts diverse regional solar calendars based on Sun transits into zodiac signs (Rashi). Explore Tamil Puthandu, Malayalam Kollam Era, Bengali Bangabda, Assamese Rongali Bihu, and Nepali Bikram Sambat.
Diversity in Unity: Solar Transits Across States
While North India primarily relies on lunar Vikram Samvat for month calculations, coastal and eastern Indian states follow sidereal solar calendars. The transition from one solar month to another occurs when the Sun transits into a new zodiac sign (Sankranti).
| State / Region | Calendar System | New Year Festival | Approximate Start Date |
|---|---|---|---|
| Tamil Nadu | Tamil Calendar (Sidereal) | Puthandu (Chithirai 1) | April 14 |
| Kerala | Kollavarsham (Kollam Era) | Chingam 1 (or Vishu in Medam) | August 17 / April 14 |
| West Bengal | Bangabda (Bengali Era) | Poila Boishakh | April 14 / 15 |
| Assam | Bhaskarabda / Bihu | Rongali Bihu (Bohag 1) | April 14 |
| Odisha | Odia Solar Panjika | Maha Vishuva Sankranti | April 14 |
| Nepal | Bikram Sambat (BS) | Nawa Barsha (Baisakh 1) | April 14 |
Frequently Asked Questions
Q: Why do most regional solar new years fall on mid-April?
Because mid-April marks Mesha Sankranti, when the Sun enters Mesha Rashi (Aries, the 0-degree point of the sidereal zodiac), signaling the astronomical spring equinox.