Milestone·Rashidun
Umar Adopts the Hijri Calendar
- Date
- 638 CE17 AH1,388 years ago
- Place
- Medina, Rashidun Caliphate
- People
- Umar ibn al-Khattab
The Hijri calendar was adopted under Caliph Umar in 638, which corresponds to 17 AH. The calendar counts years from the Prophet's migration to Medina in 622. Before this, Arabs used several systems of dating, and letters from governors sometimes lacked a clear date. The lunar Hijri calendar still sets the dates of Ramadan, Hajj and Eid.
Why it matters
The Hijri calendar is still used to set the dates of Islamic worship and festivals around the world.