During whose caliphate did the Islamic calendar (Hijri calendar) begin?
A
Umar bin Khattab (RA)
B
Abu Bakr (RA)
C
Usman bin Affan (RA)
D
Ali bin Abi Talib (RA)
Correct Answer: Option A — Umar bin Khattab (RA)
Explanation:
The Islamic Hijri calendar was formally introduced during the caliphate of Hazrat Umar (RA), taking the year of the Prophet's migration to Madinah as its starting point.