Bengali calendar

The Bengali Calendar or Bangla Calendar (Bengali: বঙ্গাব্দ, romanized: Bôṅgābdô, colloquially বাংলা সন, Bāṅlā Sôn or বাংলা সাল, Bāṅlā Sāl, "Bangla Year") is a solar calendar used in the Bengal region of the Indian subcontinent. In contrast to the traditional Indian Hindu calendar, which begins with the month Chaitra, The Bengali Calendar starts with Baishakh. A revised version of the Bangladeshi calendar is officially used in Bangladesh, while an earlier, traditional version continues to be followed in the Indian states of West Bengal, Tripura, and Assam. The Bengali calendar began in 590–600 CE to commemorate the ascension of Shashanka, the first independent king in Bengal's unified polity. Some modifications were done to the original calendar during Mughal emperor Akbar's era, to facilitate the collection of land revenue at the start of bengali harvesting season. The first day of the Bengali year is known as Pohela Boishakh (1st of Boishakh) which is a public holiday in Bangladesh.

The Bengali era is called Bengali Sambat (BS) and has a zero year that starts in 593/594 CE. It is 594 less than the AD or CE year in the Gregorian calendar if it is before Pohela Boishakh, or 593 less if after Pohela Boishakh.