The auspicious occasion is annually marked with various ceremonies and rituals in different cities on the 18th of Dhu al-Hijjah on the Islamic calendar.
On March 10, 632 CE, in the tenth year of Hijra, Prophet Mohammad (PBUH) received a revelation from God, ordering him to halt the pilgrims at a pond called Khum, a place near Mecca, and to designate Imam Ali (PBUH) as his successor in guiding and ruling Muslims.
Eid al-Ghadeer is also known as Eid al-Akbar (the greatest Eid) in Islamic narrations, since Muslims believe that the mission of all the previous messengers of Allah became accomplished on this day; Press TV reported.