Reformed Bengali Calendar
The reformed Bengali calendar was introduced on February 17, 1966.
history
The traditional Bengali calendar is based on the sidereal year , and the months vary in length in different years. The new calendar should:
- be an improvement on the traditional calendar.
- based on the tropical year .
- Have fixed length months.
The year
The year is a tropical year and begins when the sun enters the Aries zodiac sign. The common year consists of 365 days, the leap year of 366 days. The leap day is added to the month before last.
The year count
The years are counted continuously according to the Bengali Era (BS). This count builds on the count of the traditional Bengali calendar. The Mughal Mogul Akbar stipulated in 1584 that the count should coincide with the Hijra count . The year of his accession to the throne 963 AH was therefore the year 963 BS = 1555/56 AD. To determine 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 begins when the sun enters the zodiac sign Aries.
The circuit
The year has a length of 365 days. However, since the tropical year currently has a length of 365.242190 days, an additional leap day has to be inserted approximately every four years in order to match the seasons. In the leap year, the month of Falgun is extended by 1 day to 31 days. The leap years are linked to the leap years of the Gregorian calendar. Add 594 to the Bengali year and apply the switching rules of the Gregorian calendar: If the number is divisible by 4 without a remainder, the year is a leap year, but if the number is also divisible by 400 without a remainder, the year is not a leap year. Which dates of the Reformed Bengali calendar shift in the leap year compared to the Gregorian calendar can be seen in the following table:
| Common year | Leap year | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| bengali | Gregorian | bengali | Gregorian | |||||||||
| ১ | ফাল্গুন | 1. | Falgun | 13. | February | ১ | ফাল্গুন | 1. | Falgun | 13. | February | |
| : | : | : | : | |||||||||
| ১৬ | ফাল্গুন | 16. | Falgun | 28. | February | ১৬ | ফাল্গুন | 16. | Falgun | 28. | February | |
| ১৭ | ফাল্গুন | 17th | Falgun | 1. | March | ১৭ | ফাল্গুন | 17th | Falgun | 29 | February | |
| ১৮ | ফাল্গুন | 18th | Falgun | 2. | March | ১৮ | ফাল্গুন | 18th | Falgun | 1. | March | |
| : | : | : | : | |||||||||
| ৩০ | ফাল্গুন | 30th | Falgun | 14th | March | ৩০ | ফাল্গুন | 30th | Falgun | 13. | March | |
| ≡≡≡≡ | ≡≡≡≡ | ৩১ | ফাল্গুন | 31. | Falgun | 14th | March | |||||
| ১ | চৈত্র | 1. | Choitro | 15th | March | १ | চৈত্র | 1. | Choitro | 15th | March | |
| : | : | : | : | |||||||||
| ৩০ | চৈত্র | 30th | Choitro | 13. | April | ৩০ | চৈত্র | 30th | Choitro | 13. | April | |
The precision
With a length of 146,097 days, the calendar deviates by 0.124 days in 400 tropical years or by 1 day in around 3225 years.
The month
The beginning of the month
The month begins roughly with the entry of the sun into a new zodiac sign.
The length of the month
Since the earth's orbit around the sun is an ellipse, the time it takes for the sun to apparently travel through the ecliptic varies for the individual zodiac signs. To adjust the length of the months to the apparent course of the sun, the first five months have 30 days, the remaining seven months 31 days.
The month names
The months were named like the months in the traditional Bengali calendar. The following table gives the Bengali names of the months, their length and the corresponding beginning of the month in the Gregorian calendar:
| Bengali | transcription | Month length in days | Beginning of the month in the Gregorian calendar |
|---|---|---|---|
| বৈশাখ | Boishakh | 31 | April 14th |
| জ্যৈষ্ঠ | Jyoishtho | 31 | May 15 |
| আষাঢ় | Asharh | 31 | 15th June |
| শ্রাবণ | Shrabon | 31 | 16th of July |
| ভাদ্র | Bhadro | 31 | August 16 |
| আশ্বিন | Ashbin | 30th | 16th September |
| কার্তিক | Kartik | 30th | October, 16th |
| অগ্রহায়ণ | Ogrohayon | 30th | 15th of November |
| পৌষ | Poush | 30th | 15th December |
| মাঘ | Magh | 30th | January 14th |
| ফাল্গুন | Falgun | 30th | 13th February |
| চৈত্র | Choitro | 30th | March, 15 |
The days of a month are counted from 1 to 30 or 31. The Bengali numerals can be found under Bengali numerals .
The week
The week
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 calendar |
|---|---|---|
| সোমবার | Shombar | Monday |
| মঙ্গলবার | Monggolbar | Tuesday |
| বুধবার | Budhbar | Wednesday |
| বৃহস্পতিবার | Brihoshpotibar | Thursday |
| শুক্রবার | Shukrobar | Friday |
| শনিবার | Shonibar | Saturday |
| রবিবার | Robibar | Sunday |
See also
Web links
Remarks
Individual evidence
- ↑ FK Ginzel: Handbook of mathematical and technical chronology, Leipzig 1906, Vol. I, p. 394