Ramadan is the ninth month of the year for Muslims, who follow the lunar calendar. The holiday takes place 13 days earlier each year of the solar calendar.

This year, Ramadan will begin the morning after the first sighting of a new moon on Nov. 16, and end with the rising of the new moon four weeks later.

The end of Ramadan is marked by a joyous celebration called Id al-Fitr or Eid-ul-Fitr that lasts three days in some Muslim countries.

During this month, all healthy adult Muslims abstain from food, drink, including water, smoking, and sexual activity from sunrise to sunset. The month is to be devoted to reflection and spiritual discipline, as well as the reading of the Quran, Islam’s holy book revealed to the prophet Mohammed by Allah during the final days of Ramadan.

Followers also are expected to perform good deeds and pray more often than the usual five times a day, including two hours each evening in a mosque with other Muslims, if possible.

The Ramadan fast is mandatory for Muslims. To break the fast during the month is similar to committing a sin for Christians.

Children usually begin fasting at the age of 12. Pregnant women and the sick are not expected to fast, but can make it up at another time.

Muslims believe fasting teaches patience and compassion and also earns them special favor with Allah. Any good deed done during Ramadan is amplified in the eyes of God.