section_path: History/Influence of Islamic Calendar
section_name: Influence of Islamic Calendar
paragraph_text: Influence of Islamic Calendar
  
  Another theory is that the calendar was first 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. Yet another theory states that the Sasanka calendar was adopted by Alauddin Husain Shah when he witnessed the difficulty with collecting land revenue by the Hijri calendar.
  
  During the Mughal rule, land taxes were collected from Bengali people according to the Islamic Hijri calendar. This calendar was a lunar calendar, and its new year did not coincide with the solar agricultural cycles. The current Bengali calendar owes its origin in Bengal to the rule of Mughal Emperor Akbar who adopted it to time the tax year to the harvest. The Bangla year was therewith called Bangabda. Akbar asked the royal astronomer Fathullah Shirazi to create a new calendar by combining the lunar Islamic calendar and solar Hindu calendar already in use, and this was known as Fasholi shan (harvest calendar). According to some historians, this started the Bengali calendar. According to Shamsuzzaman Khan, it could be Nawab Murshid Quli Khan, a Mughal governor, who first used the tradition of Punyaho as "a day for ceremonial land tax collection", and used Akbar's fiscal policy to start the Bangla calendar.
  
  It is unclear whether it was adopted by Hussain Shah or Akbar. The tradition to use the Bengali calendar may have been started by Hussain Shah before Akbar. According to Amartya Sen, Akbar's official calendar "Tarikh-ilahi" with the zero year of 1556 was a blend of pre-existing Hindu and Islamic calendars. It was not used much in India outside of Akbar's Mughal court, and after his death the calendar he launched was abandoned. However, adds Sen, there are traces of the "Tarikh-ilahi" that survive in the Bengali calendar. Regardless of who adopted the Bengali calendar and the new year, states Sen, it helped collect land taxes after the spring harvest based on traditional Bengali calendar, because the Islamic Hijri calendar created administrative difficulties in setting the collection date. The government and newspapers of Bangladesh widely use the term Bangla shal (B.S.). For example, the last paragraph in the preamble of the Constitution of Bangladesh reads "In our Constituent Assembly, this eighteenth day of Kartick, 1379 B.S., corresponding to the fourth day of November, 1972 A.D., do hereby adopt, enact and give to ourselves this Constitution." The zero year in the Bangladeshi calendar era is 593 CE.
  
  Shamsuzzaman Khan wrote, "that it is called Bangla san or saal, which are Arabic and Parsee words respectively, suggests that it was introduced by a Muslim king or sultan." In contrast, according to Sen, its traditional name is Bangabda. In the era of the Akbar, the calendar was called as Tarikh-e-Elahi (তারিখ-ই ইলাহি). 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. According to Banglapedia, 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. This calendar is the foundation of the calendar that has been in use by the people of Bangladesh.