This Thursday marks the Muslim observance of the "Day of 'Ashura." The word 'ashura literally means "tenth" in Arabic, and is named for the day of the month on which it falls (the tenth day of Muharram, this first month of the Islamic year). 'Ashura is an ancient observance that is now recognized for different reasons and in different ways among Sunni and Shi'a Muslims.
Among Sunni Muslims, the month of Muharram and the Day of 'Ashura itself is a simple remembrance of the Prophet Moses and his liberation from the Pharoah. It is strongly recommended, but not required, to spend two days fasting on and around the Day of 'Ashura.
Among Shi'a Muslims, however, the days leading up to 'Ashura, and the remembrance of the day itself, are very mournful and grief-filled. The days are filled with passion plays, assemblies, and public displays of grief over the martyrdom of Husayn in 680 C.E.
Learn more about 'Ashura.