Which event marks year zero of the Muslim calendar and Muhammad's flight from Mecca to Medina?

• A. Conquest of Mecca
• B. Hijrah
• C. Battle of Badr
• D. Birth of Muhammad

Answer: (B)

The event that marks the start of the Muslim calendar is the Hijrah—the migration of Muhammad and his followers from Mecca to Medina in 622 CE. This move represents a turning point where the Muslim community established a new, durable presence in Medina, enabling the organization of the early Muslim state and community. Because the calendar is counted from this moment, the years are labeled Anno Hegirae (AH), starting with the year that begins at or after the Hijrah.

Other events listed are significant but occur after the Hijrah and do not inaugurate the calendar. The Conquest of Mecca happened later as Muslims expanded their position in the region, the Battle of Badr occurred shortly after the migration but is a notable battle rather than a calendar starting point, and the birth of Muhammad occurred long before the Hijrah. The Hijrah is the defining moment that sets the clock for Islamic time.