Bengali Calendar - Leap Year

Leap Year

Although the sidereal solar calendar is followed in West Bengal, India, the number of days in the months are determined by the true motion of the Sun through the zodiac. In this calendar, seven is subtracted from the year, and the result is divided by 39. If after the division the remainder (= (year - 7) / 39) is zero or is evenly divisible by 4, the year is then designated as a leap year and contains 366 days, with the last month, Choitro, taking 31 days. There are 10 leap years in every 39 years, although an extraordinary revision may be required over a long time.

According to the new calendar system in Bangladesh, Falgun (which begins mid-February) has 31 days every four years. To keep pace with the Gregorian calendar, the Bengali leap years are those whose corresponding Gregorian calendar year is counted as a leap year. For example, Falgun 1410 was considered a Bengali leap month, as it fell during the Gregorian leap month of February 2004.