Many Muslims in India observe Milad un-Nabi, which commemorates the Prophet Muhammad's (or Mohammad's) birthday. Milad un-Nabi is a gazetted holiday in India and is also known as Nabi Day, Mawlid, Mohammad's Birthday or the Prophet's Birthday. It is celebrated in the third month of the Islamic calendar. While the Shias celebrate it on the 17th of the month, the Sunnis celebrate on the 12th of the month, according to the Islamic calendar. The date of this festival varies in the Gregorian calendar.