Bengali calendar

The Bengali Calendar or Bangla Calendar (বঙ্গাব্দ Bônggabdô or Banggabda) is a solar calendar used in the region of Bengal. A revised version of the calendar is the national and official calendar in Bangladesh and an earlier version of the calendar is followed in the Indian states of West Bengal, Tripura and Assam. The New Year in the Bengali calendar is known as Pôhela Bôishakh.

The Bengali Era (BS) or Anno Bengal (AB, Latin for: in the year of Bengal), the Bengali year (বাংলা সন Bangla Sôn, বাংলা সাল Bangla sal) is 594 less than the AD or CE year in the Gregorian calendar if it is before Pôhela Bôishakh, or 593 less if after Pôhela Bôishakh.

The revised version of the Bengali calendar was officially adopted in Bangladesh in 1987. However, it is not followed in India where the unrevised (non-revised) traditional version continues to be followed due to occurrence of Hindu festivals based on a particular sidereal solar day. [1]


The Bengali calendar is a solar calendar. [1] [2]

The origin of Bônggabdô or Bengali Year (Bangla Year) is debated, with primarily two hypotheses. The development of the Bengali calendar is often attributed to King of Gour, Shashanka as the starting date (12 or 14 April 594 CE) falls squarely within his reign. [1] [3] The solar calendar is based on the Surya Siddhanta, a Sanskrit astronomical text. [1]

Another theory is that the calendar was developed by Alauddin Husain Shah (reign 1494–1519), a Hussain Shahi sultan of Bengal by combining the lunar Islamic calendar (Hijri) with the solar calendar, prevalent in Bengal. [3]

All theories agree that the Mughal Emperor, Akbar (reign 1556 – 1605) was instrumental in "promulgating" the Bengali calendar. Akbar modified, developed and re introduced the Bengali Calendar in order to make tax collection easier in Bengal. The calendar was then called as Tarikh-e-Elahi (তারিখ-ই ইলাহি). Akbar changed the practice of agricultural tax collection which had been according to the Islamic calendar and ordered an improvement of the calendar systems, because the lunar Islamic calendar did not agree with the harvest sessions and the farmers faced severe difficulties in paying taxes out of season. Some sources credit the idea to the finance minister of Akbar, Todar Mal. [1] [2] [3]

Akbar's royal astronomer Fathullah Shirazi developed the Bengali calendar, by synthesizing the Lunar Islamic and Solar Hindu calendars. The calendar started with the Islamic calendar value, but the Sanskrit month names were used from the earlier version. [1] The distinctive characteristic of the Bengali year was that rather than being a lunar calendar, it was based on a union of the solar and lunar year. This was essentially a great promotion as the solar and lunar years were formulated in very diverse systems.

Primarily this calendar was named as "Fasli Sôn" and then "Bônggabdô". The Bengali Year was launched on 1584 AD or 992 AH (Hijri), but was dated from the year 1556 AD or 963 AH. This was the day that Akbar defeated Hemu in the clash of Panipat to ascend the throne. The month of Muharram in the year 963 AH was equal to the month of Boishakh in the Bengali calendar, and so Boishakh month has continued to be the first month of the Bengali calendar. [4][ better source needed]

In the "Tarikh-e-Elahi" version of the calendar, each day of the month had a separate name, and the months had different names from what they have now. Akbar's grandson Shah Jahan reformed the calendar to use a seven-day week that begins on Sunday, and the names of the months were changed at an unknown time to match the month names of the existing Saka calendar. [2] [5]