Bengali (West Bengal)
The traditional panjika · sidereal months by the Surya Siddhanta
The Bangabda in its traditional form, kept in West Bengal, Tripura and Assam and printed each year in the panjika, the Bengali almanac. A month begins the day after a sankranti — the moment the sun enters a new sidereal sign — so months run 29 to 32 days and Poila Boishakh falls on 14 or 15 April. The sun in question is not the one overhead but the one described in the Surya Siddhanta, a Sanskrit astronomical treatise of the first millennium, whose model now trails the sky by up to sixteen hours; reckoned by modern astronomy, a good third of the months would open a day earlier than the almanacs have them. When a sankranti lands near midnight in Kolkata, minutes decide the date: in September 2026 the state government moved its Vishwakarma Puja holiday from the 17th to the 18th with only days to spare. The dates here follow the published almanacs, checked month by month from 1419 to 1435; further out they follow the rule alone. Bangladesh reformed all this away in 1987, which is why its calendar reads up to three days ahead.
In UTC at 16:17 on November 4, 2026, this calendar read 17 Kartik 1433. The reading above is live, in your own time zone.
At a glance
- Type
- Solar — sidereal, by the sun of the Surya Siddhanta
- Origin
- The traditional reckoning, as the panjika almanacs publish it each year
- Year
- 365 or 366 days, opening on 14 or 15 April
- Months
- 12 — of 29 to 32 days, each running from one sankranti to the next
- Week
- 7 days
- Leap rule
- None as such — the months’ own varying lengths absorb the difference
- Counts from
- The Bengali era — 593 behind the Common Era from mid-April on
- Where it’s used
- West Bengal, Tripura and Assam, for festivals and the cultural year
- How it’s worked out here
- The Surya Siddhanta sun, checked month by month against the published almanacs for 1419–1435 BS; the rule alone beyond them
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