Convert any Gregorian date to the Hijri (Islamic) calendar or convert any Hijri date back to Gregorian instantly. The Islamic calendar is a lunar calendar of 12 months used to determine Ramadan fasting, Eid al-Fitr, Eid al-Adha, Hajj, and all other Islamic observances.
The Hijri calendar began in 622 CE marking the Prophet's migration (Hijra) from Mecca to Medina. A Hijri year is approximately 354 days, making it 10 to 11 days shorter than the Gregorian year.