The History of the Islamic Era: After the Hijrah of the Last Prophet (ﷺ)

The establishment of the Islamic Era was done under 'Umar ibn al-Khattab, when Companions decided to initiate it from the year of the Prophet's Hijrah. 'Umar's choice to commence the Muslim Era from Muharram, rather than Rabi‘ al-Awwal, was influenced by its historical significance. However, since the Hijrah itself took place two months later in Rabi‘ al-Awwal, this retroactive decision created a 59-day gap between the actual Hijrah date and the start of the Hijrah calendar year. Discrepancies between recorded and Hijrah Calendar dates, with a 59-day gap between the current and old Hijrah calendars' starting points cause discrepancies in many Islamic historical events so that there is need for a revival of the Old Hijrah Calendar for more precise historical dating.