Every Muslim must make the pilgrimage, or the holy journey, to Mecca at least one in their lifetime. The Hajj is a 10 day journey that starts on the 8th day of the Dhul-Hijjah, the Islamic calendar's 12th month, and concludes on the 13th day of Eid Al-Adha, the feast of the sacrifice. The Hajj is the 5th pillar of the 5 pillars of Islam.