What Event Marks The Beginning Of The Muslim Calendar. The islamic calendar, which is based purely on lunar cycles, was first introduced in 638 ce by the companions of the prophet, sallallahu alayhi wasallam, and the second khalifah, umar ibnul. The event that marks the beginning of the islamic calendar, known as year 1 ah (after hijrah), is the flight of prophet muhammad from mecca to medina, which is referred to as the hijrah.
The muslim new year marks the beginning of the islamic calendar year and its observation is on the first day of muharram, the first month of the islamic calendar. The islamic new year marks the first day of muharram, a sacred month of prayer and annual reflection.