The Hijri calendar (or Islamic calendar) is a lunar calendar used to date the religious events of Islam: Ramadan, the two Eids, Hajj, or commemorative dates like Ashura. Unlike the Gregorian (solar) calendar, it counts years from a different starting point and follows a different rhythm.
A starting point: the Hijra
The calendar begins at the Hijra (هِجْرَة) — the migration of the Prophet Muhammad ﷺ from Mecca to Medina, in 622 CE. This choice is deliberate: it's neither the Prophet's ﷺ birth nor his death that marks year 1, but the founding event of the first organised Muslim community. The calendar was officially adopted under the caliphate of Umar ibn al-Khattab, about 17 years after the Hijra itself.
Twelve lunar months
The Hijri year has 12 months, each beginning with the sighting (or calculation) of the new crescent moon: Muharram, Safar, Rabi al-Awwal, Rabi al-Thani, Jumada al-Awwal, Jumada al-Thani, Rajab, Sha'ban, Ramadan (the month of fasting), Shawwal, Dhu al-Qi'dah and Dhu al-Hijjah (the month of Hajj). Each month lasts 29 or 30 days depending on the actual lunar cycle, giving a year of 354 or 355 days — about 11 days shorter than a Gregorian year.
Why dates "drift" every year
This 11-day gap explains why Ramadan, for example, never falls in the same season two years running in the Gregorian calendar: it gradually moves forward, passing through every season over a cycle of about 33 years. This is a fundamental difference from a solar calendar, where months stay aligned with the seasons.
Calculation or observation?
Two approaches coexist for determining the start of a month: direct observation of the lunar crescent (traditionally used in many countries) and astronomical calculation — of which the Umm al-Qura calendar, used in Saudi Arabia, is a notable example. A third, simpler tool is the tabular Hijri calendar: a fixed arithmetic calculation (a 30-year cycle with 11 leap years) that gives a reliable day-accurate match in most cases, but can differ by a day or two from actual observation. That's the method our online Hijri ↔ Gregorian converter uses, handy for a quick conversion — to be confirmed by the official announcement for any important religious date.
Frequently asked questions
What year is it in the Hijri calendar?
Use our Hijri ↔ Gregorian converter to find today's date and convert any date.
Why does the Islamic calendar have 354 days instead of 365?
Because it's lunar: its 12 months follow the moon's cycle (29-30 days each), not the sun's.
Is the Hijri calendar the same everywhere in the Muslim world?
Not always to the exact day: some countries rely on local moon-sighting, others on a calculated calendar like Umm al-Qura, which can create a one-day gap between regions.
