Many Muslims observe the start of the Islamic New Year on the first day of Muharram, which is the first month in the Islamic calendar.
Muharram is one of the four sanctified months in the Islamic calendar. Some Muslim Americans choose to fast during this month, although fasting is not obligatory. Many Muslims engage in voluntary prayer, including evening prayer, during Muharram.
The Day of Ashura (or Ashurah) is known as the most sacred day in the month of Muharram. It is the 10th day of Muharram and is a day of fasting for many Sunni Muslims. Many Shi’a Muslims use the day to commemorate the martyrdom of Husayn ibn Ali in 680 CE. Some Muslims give to charity on this day.
Regional customs or moon sightings may cause a variation of the date for Islamic holidays, which begin at sundown the day before the date specified for the holiday. The Islamic calendar is lunar and the days begin at sunset, so there may be one-day error depending on when the New Moon is first seen.