When Does Muslim Calendar Begin. Today marks the 1st of muḥarram, which means it is the beginning of the new islamic year. Consequently, 622 ad (the year of the prophet’s migration) became the.
The islamic calendar is based on lunar months, which begin when the thin crescent moon is actually sighted in the western sky after sunset a day or so after new moon. The islamic calendar is based on a lunar year of 12 full lunar (monthly) cycles, taking 354 days.