Eid Mubarak! The festival of Eid ul Fitr commemorates the end of the the Islamic month of Ramadan, during which Muslims fast during daylight hours from all food and drink—including water—and spend large portions of each night in worship & meditation.
The holiday lasts three days, and the traditional greetings are Eid Mubarak and Eid Saeed, save in Turkic traditions, where the greeting is Bayraminiz Mubarek.