The History of the Hijri Calendar: Why It Begins with the Prophet's Migration

Almost every calendar has a starting point. The Gregorian calendar counts time from the birth of Jesus Christ. The Buddhist calendar begins from the death of the Buddha. Many ancient kingdoms used the coronation of a king as the start of their year count. The Islamic calendar took a different path. It did not begin with the birth of the Prophet Muhammad (PBUH), nor with the first revelation, nor even with his death. The first year of the Islamic calendar instead originates from a journey of approximately 450 kilometres between Makkah and Madinah. This choice was made during the caliphate of Umar bin Khattab, more than a decade after the Prophet’s passing. To this day, that decision remains the basis for timekeeping for over a billion Muslims.

Long before the Hijri calendar was established, Arab society already recognised a lunar-based system of months. Names such as Muharram, Safar, Ramadan, Shawwal, and Dhulhijjah had been used since pre-Islamic times. They also recognised four sacred months that were honoured and during which warfare was halted. What they lacked was a numbered year. Instead, time was marked by major, memorable events. There was the Year of the Elephant, when Abrahah’s army attacked Makkah; the Year of Fijar, when inter-tribal war broke out; and the year the Kaaba was renovated after a great flood. This system persisted into the caliphate of Umar bin Khattab. A problem arose when the Islamic territory expanded and governmental administration became more complex. In one account, Abu Musa Al-Asy’ari, then governor of Basra, sent a letter to Umar complaining, “We receive letters from the Commander of the Faithful, but we do not know whether a letter was written in Sha’ban of this year or the previous one.” The complaint seemed simple, but for an expanding government, the ambiguity of dates affected legal certainty, archiving, and policy implementation. Umar then gathered the companions to find a solution.

During the forum, several proposals were put forward. Ibn Hajar Al-Asqalani explains in Fathul Bari that the year of the Prophet’s birth and the year of his appointment as a messenger were still debated. Meanwhile, the year of his death was considered inappropriate because it was associated with a sad event. The choice ultimately fell on the Hijrah. The migration of Prophet Muhammad (PBUH) and his followers to Madinah in 622 CE was designated as the starting point of the Islamic calendar. The reason was not merely that the Hijrah was a major event. What was considered important was the transformation that followed. Before the Hijrah, Muslims were a small community living as a minority in Makkah. They had no political authority, government, or independent social institutions. The situation changed in Madinah. There, the Charter of Madinah was born, regulating relations between various community groups. Markets developed with more structured rules. Zakat evolved into a more organised social instrument. The Muslim community also gained clearer leadership and governance. The Hijrah became the point when Islam was no longer just a religious community, but also a society with institutions. For this reason, the calendar’s starting point was not the birth of an individual, but the moment of a community’s transformation.

Another little-known fact is that the Hijrah occurred in Rabiul Awal, yet the Islamic New Year begins in Muharram. This decision also emerged from deliberation among the companions. In various accounts, Uthman bin Affan proposed Muharram as the first month because it had long been considered the start of the year in Arab tradition. Muharram also comes after the Hajj season ends, when society begins a new cycle. Moreover, the resolve to migrate strengthened after the Pledge of Aqabah in Dhulhijjah, making Muharram the first month following that commitment. In other words, the Hijri calendar does not begin on the day the migration took place, but from the moment the change was planned.

Every civilisation has its own way of remembering its history. Some choose the birth of a great figure, others a victory in war, the founding of a dynasty, or the coronation of a ruler. The Islamic calendar chose something different. Its starting point is an event that marked the birth of a new order. Thus, the Hijri calendar is not merely a dating system. It is also a reminder of the moment a community began to build its institutions, rules, and the direction of its own history.