What is Panjika? Understanding the Bengali Calendar
By Siddhartha Banerjee • Panjika Science Contributor
The Bengali Panjika (পঞ্জিকা) is the astronomical almanac that governs Bengali daily life, religious festivals, and auspicious timings (Muhurats). Dating back centuries, the Panjika is more than just a calendar—it is a mathematical chart of solar and lunar movements.
Origins of the Bengali Calendar (Bangabda)
The Bengali calendar era, Bangabda (বঙ্গাব্দ), is widely believed to have been introduced during the reign of the Mughal Emperor Akbar in 1584 CE.
To streamline tax collection in Bengal (which relied on the harvest seasons), Akbar’s royal astronomer, Fathullah Shirazi, combined the Islamic lunar calendar with the Hindu solar calendar. The era was set to begin retrospectively from the coronation of Akbar in 1556 CE (which corresponds to 963 AH in the lunar calendar, or 1402 BS in the Bengali era).
Traditional vs. Revised Panjika
Bengalis follow two primary versions of the calendar:
- Traditional Sidereal Solar Calendar (West Bengal, India): Based on the Surya Siddhanta astronomical texts. Month lengths vary (29 to 32 days) based on the exact time the Sun transitions from one zodiac sign (Rashi) to another.
- Revised Calendar (Bangladesh): Standardized by the Bangla Academy in 1966 and updated in 2019. The first six months have exactly 31 days, the next five have 30 days, and Falgun has 29 days (30 in leap years). This keeps the calendar aligned precisely with the Gregorian calendar, starting Poila Boishakh on April 14th every year.
Frequently Asked Questions
How is the Bengali year computed?
Subtract 593 from the Gregorian year for dates after Poila Boishakh (mid-April). Subtract 594 for dates before.
Why do traditional Bengali months have varying lengths?
Because the Sun’s transit speed across different zodiac signs is not uniform due to the Earth’s elliptical orbit.