Bengali calendar

The Bangladeshi national calendar (Bengali: বঙ্গাব্দ, romanized: Bôṅgābdô) officially and commonly, is a civil calendar used in Bangladesh, alongside the Gregorian calendar. With roots in the ancient calendars of the region, it is based on Tarikh-e-Elahi (Divine Era), introduced by the Mughal Emperor Akbar on 10/11 March 1584. The calendar is generally 593 years behind the Gregorian calendar, meaning the year zero in the calendar is 593 CE.

The Bengali calendar began in 590–600 CE to commemorate the ascension of Shashanka, the first independent king in Bengal's unified polity. The first day of the Bengali year is known as Poila Boishakh (1st of Boishakh), which is a public holiday in West Bengal, Assam and Tripura.

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.

The calendar is important for Bangladeshi agriculture, as well as festivals and traditional record keeping for revenue and taxation. Bangladeshi land revenues are still collected by the government in line with this calendar. The calendar's new year day, Pohela Boishakh, is a national holiday.

The government and newspapers of Bangladesh widely use the abbreviation B.S. (Bangla Son, or Bangla Sal, or Bangla Sombat) for Bangladeshi calendar era. 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."

History

Origins

The Saka Era was widely used in Bengal prior to the arrival of Muslim rule in the region, according to various epigraphical evidence. The Bikrami calendar was in use by the Bengali people of the region. This calendar was named after King Vikramaditya with a zero date of 57 BCE. In rural Bengali communities, the Bengali calendar is credited to "Bikromaditto", like many other parts of India and Nepal. However, unlike these regions where it starts in 57 BCE, the modern Bangladeshi and Bengali calendar starts from 593 CE, suggesting that the starting point refers to the Bengali king Shashaka's ascent to the throne.

Hindu influence

Some historians attribute the Bengali calendar to the 7th-century Bengali king Shashanka, whose reign covered the Bengali era of 594 CE. The term Bangabda (Bangla year) is found too in two Shiva temples many centuries older than the Akbar era, suggesting that a Bengali calendar existed long before Akbar's time.

Hindus developed a calendar system in ancient times. Jyotisha, one of the six ancient Vedangas, was the Vedic era field of tracking and predicting the movements of astronomical bodies in order to keep time. The ancient Indian culture developed a sophisticated time keeping methodology and calendars for Vedic rituals.

The Hindu Vikrami calendar is named after King Vikramaditya and starts in 57 BCE. In rural Bengali communities of India, the Bengali calendar is credited to "Bikromaditto", like many other parts of India and Nepal. However, unlike these regions where it starts in 57 BCE, the Bengali calendar starts from 593, suggesting that the starting reference year was adjusted at some point. Various dynasties whose territories extended into Bengal, prior to the early 13th century, used the Vikrami calendar. For example, Buddhist texts and inscriptions created in the Pala Empire era mention "Vikrama" and the months such as Ashvin, a system found in Sanskrit texts elsewhere in the ancient and medieval Indian subcontinent.

Hindu scholars attempted to keep time by observing and calculating the cycles of the Sun (Surya), Moon, and the planets. These calculations about the Sun appear in various Sanskrit astronomical texts in Sanskrit, such as the 5th-century Aryabhatiya by Aryabhata, the 6th-century Romaka by Latadeva and Panca Siddhantika by Varahamihira, the 7th-century Khandakhadyaka by Brahmagupta, and the 8th-century Sisyadhivrddida by Lalla. These texts present Surya and various planets and estimate the characteristics of the respective planetary motion. Other texts, such as Surya Siddhanta, are dated to have been completed sometime between the 5th century and 10th century.

The current Bengali calendar in use by Bengali people in the Indian states such as West Bengal, Tripura, Assam, and Jharkhand is based on the Sanskrit text Surya Siddhanta and includes the modifications introduced during the reign of Shashanka, the first independent ruler of Gauda. The timeline of Shashanka becoming the sovereign ruler of Bengal, rising from a territorial ruler, matches with the first year of Bangabda. It retains the historic Sanskrit names of the months, with the first month as Baishakh. Their calendar remains tied to the Hindu calendar system and is used to set the various Bengali Hindu festivals.

Influence of the 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. 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.

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 the 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 Akbar, the calendar was called 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.

Akbar's influence

Crop cycle's depended on solar calendars. The Islamic lunar calendar of the Mughal government, before Akbar's era caused problems in tax collection since the lunar year was shorter than the solar year by about eleven days per year. Akbar commissioned his astronomer Fathullah Shirazi to develop a new syncretic calendar to allow land tax and crop tax collection according to the harvest cycles. In 1584, Emperor Akbar commissioned a new calendar as part of tax collection reforms.

Shirazi's new calendar was known as the Tarikh-e-Ilahi (God's Era). It used 1556 as the zero year, the year of Akbar's ascension to the throne. The Tarikh-e-Ilahi calendar were one of the syncretic reforms Akbar introduced, along with a new religion called Din-ilahi, a syncretic faith that integrated Islam and Indian religious ideas. However, Akbar's ideas were almost entirely abandoned after his death, and only traces of the Tarikh-e-Ilahi calendar survive in the modern Bengali calendar, according to Amartya Sen.

Shamsuzzaman Khan believed that Nawab Murshid Quli Khan was responsible for widely implementing the tax collection according to the Bengali calendar throughout Bengal. Khan promoted celebrations of the Punyaha, a ceremonial collection of land taxes. The calendar year became known as the Bangla san in Arabic and Bangla sal in Persian; both terms mean the Bangla Year.

Modern revisions and adoption

In 1966, a committee headed by Muhammad Shahidullah was appointed in East Pakistan to reform the traditional Bengali calendar and making it independent of Hindu astrological influences. It proposed the first five months 31 days long, rest 30 days each, with the month of Falgun adjusted to 31 days in every leap year. This was officially adopted by Bangladesh in 1987.

In 2018, the Bangladesh government planned to modify the Bangladeshi calendar again. The changes were done to match national days with West. As a result of the modification, Kartik started on Thursday (17 October 2019) and the dry season was delayed by a day as the revised calendar went into effect from Wednesday (16 October 2019).