Zul-Hijjah is the twelfth and final month of the Islamic lunar calendar. It holds great significance for Muslims, as it is the month during which the annual pilgrimage, known as Hajj, takes place. This pilgrimage is one of the Five Pillars of Islam and is obligatory for all Muslims who are physically and financially able to perform it at least once in their lifetime. The month of Zul-Hijjah also includes the celebration of Eid al-Adha, or the Festival of Sacrifice, which occurs on the 10th day. This festival commemorates the willingness of Ibrahim (Abraham) to sacrifice his son in obedience to God. During this time, Muslims around the world engage in prayers, feasting, and acts of charity.