What Event Marks The Beginning Of The Islamic Calendar. The event that marks the start of the islamic calendar is the hijrah, which refers to the migration of the prophet muhammad and his followers from mecca to the city of medina in. The islamic new year, which is the first day of the islamic calendar, dates back to the migration of the prophet muhammad and his followers from mecca to medina in the year 622 c.e., which is known as the hijra.
The event marks the beginning of a second phase of the islamic movement. It is the phase when madinah became the center of an islamic state.