The Bengali calendar

What kind of calendar it is

The Bengali calendar, called the Bangabda or Bangla Sal, is a solar calendar used in West Bengal, Tripura, Bangladesh and by Bengalis around the world. Each month begins when the Sun enters a new zodiac sign, so the months sit nearly in the same place every Gregorian year. Boishakh, the first month, starts around mid April.

Two versions are in use. West Bengal keeps the traditional almanac (panjika), which counts months by the Sun's real position in the sky, so month starts can move by a day from year to year. Bangladesh adopted a revised version in the 1980s for civil use, which fixed the month lengths and the date of the New Year. Both share the same year number and the same month names.

Era and year number

The year number is the Gregorian year minus 593 after the New Year in mid April, and minus 594 from January 1 until the New Year. The origin of the era is a matter of discussion. Some writers link it to the revenue-year reform under the Mughal emperor Akbar, which converted a lunar Islamic year count into a solar one for tax collection. Others connect it to the king Shashanka of ancient Bengal. This page does not take a side, and both appear in the books.

The year changes at Poila Boishakh, not on January 1.

The twelve months

Spellings differ (Baishakh, Jyaistha, Ashar, Shrabon, Choitra). In the revised Bangladesh calendar the first five months have 31 days and most of the others 30, and the leap day goes to Falgun (later revisions, around 2019, changed some month lengths, and sources differ on the details). The traditional West Bengal almanac has no fixed leap-day month, because its month lengths follow the Sun's actual motion. Traditions differ, so check the calendar you use.

The New Year

Poila Boishakh (Pohela Boishakh in Bangladesh) is the first of Boishakh, around April 14 or 15. In Bangladesh it is fixed on April 14. In West Bengal it can fall on the 14th or the 15th, depending on the almanac. Traditions include new clothes, special meals, fairs, cultural programmes, and the new account book (halkhata) in shops. The Poila Boishakh page on this site covers the details.

Festivals that differ from the North Indian calendar

The Bengali almanac keeps all the lunar festivals too, using Amanta months. Alongside those, the solar months carry their own markers:

• Poila Boishakh, the New Year.
• Choitro Sankranti, the last day of the year, observed in many places with Charak or Gajan, a Shiva festival of village communities.
• Poush Sankranti, the harvest festival with rice-cake sweets called pithe and puli.
• Nabanna in Agrahayan, the festival of the new rice harvest.
• Durga Puja in Ashwin, the biggest festival in Bengal, falling on the same days as the all-India Navaratri.
• Kali Puja on the new moon night of Diwali, which Bengalis keep as a major festival.

How the day is reckoned

In the traditional panjika, the Bengali day is counted from sunrise. A solar month begins when the Sun enters a sign, and rules decide which civil day gets the month's first date when this happens close to midnight or sunrise. That is why two Bengali calendars can place the start of a month on adjacent days. Lunar tithis are listed beside the solar dates for religious use.

How it differs from the site's main Panchang

The site's main pages use Vikram Samvat in the Chaitradi Purnimanta style. Compared with that:

1. The Bengali months are solar and start when the Sun enters a sign. Vikram Samvat months follow the Moon.
2. The era is different. The Bangabda year is the Gregorian year minus 593 or 594, whereas Vikram Samvat is the Gregorian year plus 56 or 57.
3. The New Year is a solar event in mid April, not Chaitra Shukla Pratipada.

The religious calendar still follows the Moon. Durga Puja, Kali Puja and Saraswati Puja fall on the same tithis as on the site's main pages, so you can use the main Panchang for these.