Bengali solar calendar
The oldest references to chronology on the Indian subcontinent can be found in the Vedas , the oldest parts of which date back to around 1200 BC. Go back BC. The Jyotisha Vedanga with treatises on astronomy and astrology comes from a later period . Greek and West Asian knowledge influenced the Siddhantas (astronomical textbooks) in the first centuries AD. The Surya-Siddhanta in particular formed the basis of all calendars on the Indian subcontinent. The Arab conquerors brought the Islamic calendar with them. A Persian calendar was introduced under Mughal Akbar in 1584 in order to standardize the large number of different calendar systems for administration. However, this calendar was only used for a few decades. A modification of the traditional Hindu calendar was then used in Bengal. A reformed calendar - similar to the Indian national calendar - was introduced in 1966 in East Pakistan, today's Bangladesh . In the Indian states of West Bengal , Tripura and Assam , the Bengali calendar described here was still used.
The year is a sidereal year . In the Surya Siddhantas the length is given as 365.2587558 days (365 days 6 hours 12 minutes 36.5 seconds); other Siddhantas deviate from it by a few seconds. The actual value is 365.256360 days ( 365 days 6 hours 9 minutes 9.5 seconds ). The year consists of 365 or 366 days.
The year count
During the calendar reform of the Great Mogul Akbar in 1584 it was determined that the count of the Bengali era (BS) should coincide with the count after the Hijra . The year of his accession to the throne 963 AH was therefore the year 963 BS, also the year 1555/56 AD. Since the Bengali calendar uses a sidereal year, but the Islamic calendar uses a lunar year, the Bengali count is now 14 years ago: 1416 / 17 BS = 1431 AH = 2010/11 AD To find the year AD for a year of the Bengali era, add 593 or 594 depending on the season.
The beginning of the year
The beginning of the year is determined by the entry of the sun into the zodiac sign Aries. If the entry occurs between sunrise (beginning of the day) and midnight, the year begins on the next day, if entry occurs between midnight and sunrise, the year begins on the day after next, whereby there are still special rules.
With 365.2587558 days, the Siddhanta year is 0.0023958 days (3 minutes and 26 seconds) longer than the sidereal year with 365.256360 days. This means that it will shift against the fixed star sky by one day in around 400 years. The Siddhanta year with 365.2587558 days is 0.01656528 days (23 minutes and 51 seconds) longer than the tropical year with 365.24219052 days. This means that in around 60 years it will be shifted by one day compared to the seasons. Currently the year begins 23 days after the spring equinox.
The path that the sun apparently travels in a sidereal year is divided into 12 signs of the zodiac of 30 ° each. Since the orbit of the earth around the sun is an ellipse, the sun stands for different lengths of time in the individual signs of the zodiac during its apparent course.
The beginning of the month
The beginning of the month is determined by the entry of the sun into a new zodiac sign. If the entry occurs between sunrise (start of the day) and midnight, the month begins on the next day, if entry occurs between midnight and sunrise, the month begins on the day after next, whereby there are still special rules.
The length of the month
The sun is at its apparent path of different lengths in different zodiac signs. The time varies between 29.34806 days (29 days 8 hours 21 minutes 12 seconds) and 31.61057 days (31 days 14 hours 39 minutes 13 seconds). Accordingly, a month lasts between 29 and 32 days and can have different lengths in different years.
The month names
The months were originally named after the lunar houses ( nakshatra ), in which the sun entered a new zodiac sign. The months of the year have the following names and corresponding dates in the Gregorian calendar:
|month||১৪১৯ / 1419||১৪২০ / 1420||১৪২১ / 1421||১৪২২ / 1422||১৪২৩ / 1423|
|১||বৈশাখ||1.||Boishakh||31||14th||April 2012||31||15th||April 2013||31||15th||April 2014||31||15th||April 2015||31||14th||April 2016|
|১||জ্যৈষ্ঠ||1.||Jyoishtho||32||15th||May 2012||31||16.||May 2013||31||16.||May 2014||32||16.||May 2015||32||15th||May 2016|
|১||আষাঢ়||1.||Asharh||31||16.||June 2012||31||16.||June 2013||32||16.||June 2014||31||17th||June 2015||31||16.||June 2016|
|১||শ্রাবণ||1.||Shrabon||32||17th||July 2012||31||18th||July 2013||31||18th||July 2014||32||18th||July 2015||32||17th||July 2016|
|১||ভাদ্র||1.||Bhadro||31||18th||August 2012||31||18th||August 2013||31||18th||August 2014||31||19th||August 2015||31||18th||August 2016|
|১||আশ্বিন||1.||Ashbin||30th||18th||September 2012||31||18th||September 2013||31||18th||September 2014||30th||19th||September 2015||30th||18th||September 2016|
|১||কার্তিক||1.||Kartik||30th||18th||October 2012||29||19th||October 2013||30th||19th||October 2014||30th||19th||October 2015||30th||18th||October 2016|
|১||অগ্রহায়ণ||1.||Ogrohayon||30th||17th||November 2012||30th||17th||November 2013||29||18th||November 2014||30th||18th||November 2015||30th||17th||November 2016|
|১||পৌষ||1.||Poush||29||17th||December 2012||29||17th||December 2013||30th||17th||December 2014||29||18th||December 2015||29||17th||December 2016|
|১||মাঘ||1.||Magh||29||15th||January 2013||29||15th||January 2014||29||16.||January 2015||29||16.||January 2016||29||15th||January 2017|
|১||ফাল্গুন||1.||Falgun||30th||13.||February 2013||30th||13.||February 2014||30th||14th||February 2015||30th||14th||February 2016||30th||13.||February 2017|
|১||চৈত্র||1.||Choitro||30th||15th||March 2013||31||15th||March 2014||30th||16.||March 2015||30th||15th||March 2016||31||15th||March 2017|
The days of a month are counted from 1 to 29 or 32. The Bengali numerals can be found under Bengali numerals .
The week division is of Babylonian-Greek origin. The names are derived from the corresponding deities. The names are listed in the following table:
|bengali||transcription||in the Gregorian
- Friedrich Karl Ginzel: Handbook of mathematical and technical chronology , Volume I. Leipzig 1906–1914.
- Leow Choon Lian, Indian Calendars, National University of Singapore, 2000/2001, quoted from math.nus.edu.sg (here the page numbers are 6 larger), accessed on January 27, 2011.
- Edward M. Reingold, Nachum Dershowitz: Calendrical Calculations - The Millennium Edition . Cambridge 2001.
- L. Latham: Standard C Date / Time Library, Lawrence (KS) 1998, p. 307
- Revised Bengali Calendar in Bengali Calendar accessed on January 27, 2011
- Leow Choon Lian, Indian Calendars, National University of Singapore, 2000/2001, quoted from math.nus.edu.sg ( memento of April 17, 2018 in the Internet Archive ) (here the page numbers are 6 larger). January 2011, p. 15.
- Friedrich Karl Ginzel: Handbook of mathematical and technical chronology , Volume I. Leipzig 1906–1914, p. 341
- Friedrich Karl Ginzel: Handbuch der Mathematischen und Technischen Chronologie , Volume I. Leipzig 1906-1914, p. 342
- Leow Choon Lian, Indian Calendars, National University of Singapore, 2000/2001, quoted from math.nus.edu.sg ( Memento from April 17, 2018 in the Internet Archive ) (here the page numbers are 6 larger), accessed on January 27, 2011, p. 20
- Edward M. Reingold, Nachum Dershowitz: Calendrical Calculations - The Millennium Edition . Cambridge 2001, p. 279
- kanchanmoni , accessed March 2, 2013.
- BangaliNET , accessed March 25, 2014.
- BlazonsArt , accessed March 13, 2015.
- BlazonsArt , accessed March 22, 2016.