Which Khalifa is associated with the establishment of the Hijri calendar ?

Question

Accepted Answer

The correct option is 2:

The establishment of the Hijri calendar is centrally associated with the second Rashidun Caliph, Umar ibn Al-Khattab (often referred to simply as Umar). The need for a standardized, unified dating system arose approximately seventeen years after the Hijra (the migration of Prophet Muhammad from Mecca to Medina in 622 CE), as the rapidly expanding Islamic empire required a clear chronological framework for administrative and financial documents, such as tax collection and correspondence. Caliph Umar consulted with his council, and they collectively decided to use the Hijra itself—the moment the Muslim community migrated and established its first state—as the starting point (Year 1) of the new Islamic lunar calendar. This system officially commenced in 638 CE, establishing the Hijri era that remains in use today.

The incorrect option is 1:
Usman ibn Affan was the third Rashidun Caliph, ruling after Umar. While his reign was crucial for the expansion of the empire and the standardization of the Quran, the Hijri calendar system was already firmly established and operational under his predecessor, Umar.

The incorrect option is 3:
Abu Baqr was the first Rashidun Caliph, who succeeded Prophet Muhammad. His primary focus was maintaining the unity of the nascent Muslim state and consolidating power during the Riddah Wars (Wars of Apostasy). Although his period laid the foundation for the Caliphate, he did not formalize or institute the official Islamic dating system.

The incorrect option is 4:
Ali ibn Abi Talib was the fourth and final Rashidun Caliph. He took office many years after the calendar's implementation. His caliphate was marked by civil strife, particularly the First Fitna, and he inherited the well-established administrative structures, including the Hijri calendar, created during the reigns of Umar and Usman.