How to Calculate the Muslim Year

Islamic months begin with a visual sighting of a new moon.

The Muslim calendar, often known as the hijra or hijri calendar - begins on July 16 of the year 622 CE. This year is pivotal in Islamic history, because this is the year that Muhammad and his followers moved from Mecca to Medina, where Muhammad was offered the position of city arbitrator. Hijra, in fact, means migration. Months alternate between 29 and 30 days, with no consistent pattern. The new month is determined by the sighting of a new moon; if the night of the 29th day is cloudy and there is no moon sighting, then the month ends on the 30th evening. Each Muslim country determines the months depending on these sightings, though no month exceeds 30 days. The only reliable means of calculating a Muslim year falls with the tabular Islamic calendar, which is rejected by many Muslim scholars.

Things You'll Need

• Internet
• Date converter widget

Instructions

1. Subtract 621.57 from the Gregorian year. In other words, 2011 -- 621.57 = 1389.43.

2. Divide that number by 0.97023. Thus, 1389.43 / 0.97023 = 1432.06250. The number before the decimal is the year.

3. Check with the religious authority of the Muslim country of your choice for the Islamic year in use. Every country calculates the beginning of months and years differently and there is no standard system across the Islamic world.

Tips & Warnings

• The tabular Islamic calendar postulates cycles of 30 years, with 11 leap years of 355 days and 19 regular years of 354 days. The cycle thus drifts by a day or two every cycle. The year used in 2011 across the Islamic world is 1432; even though there is variation in moon sightings, months only vary by a day or two. The easiest way to quickly calculate the Islamic year is by an online date converter.

• Many Muslim theologians dispute the legitimacy of calculating Muslim months or years at all, they hold that this countermands Muhammad's and Allah's instructions to begin months with visual sightings of a new moon. Calculating an Islamic year using mathematical calculations is thus considered to be an aberration; the best way to know the Islamic year is to look it up.

References

• Submission.org: Islamic Calendar
• Islamic Calendar: Numbering the Years
• Islamic Finder: Hijri Calendar
• Al-Habib: Hijri Date Converter