Hijri

Hijri refers to the Islamic lunar calendar and to the era that begins with the Prophet Muhammad’s migration from Mecca to Medina, known as the hijra. The dating system uses Anno Hegirae (AH) to mark years, with 1 AH beginning in 622 CE. Because the calendar is lunar, its year is shorter than the solar Gregorian year, averaging 354 or 355 days.

The Hijri calendar has twelve months: Muharram, Safar, Rabiʿ al-awwal, Rabiʿ al-thani, Jumada al-ola, Jumada al-akhira, Rajab, Shaʿban, Ramadan, Shawwal, Dhu al-Qiʿdah, and Dhu al-Hijjah. Each month begins with the sighting of the new moon, and months alternate between 29 and 30 days in a pattern that can vary by sighting and calculation. In many contexts, a leap year adds one day to Dhu al-Hijjah, giving a 355-day year in a 30-year cycle.

Usage and significance: the Hijri calendar governs the timing of major Islamic observances such as Ramadan, Hajj, Eid al-Fitr, and Eid al-Adha. While some Muslim-majority countries use the Hijri calendar for civil purposes, others employ it alongside the Gregorian calendar. In modern administration, several civil calendars (such as Saudi Arabia’s Umm al-Qura system) provide standardized approximations of Hijri dates, while lunar sighting and astronomical calculations influence month beginnings and holidays in practice.

Overall, the Hijri calendar serves religious, historical, and cultural functions within the Muslim world, linking annual observances to a historical era anchored in the hijra.