Ramadan is the most sacred month of the year for more than 1 billion Muslims. This month of fasting, introspection, and devotion to God is one of the more physically demanding months in the Muslim calendar, but followers maintain that the spiritual rewards far outweigh the sacrifices. Believed to be the time that the sacred Muslim text, the Quran, was revealed, Muslims consider Ramadan necessary for revitalizing their spiritual lives. For one month, Muslims are required to fast during the daylight hours, and to abstain from certain behaviors, such as lying or smoking, which can taint this sacred period. The end of Ramadan is celebrated in a three-day festival called Eid al-Fitr, a time for friends and families to get together, make amends, and extend forgiveness. Ramadan describes the various customs and traditions of Ramadan and Eid al-Fitr celebrations in Africa, Asia, Europe, the Middle East, North America, and Oceania and how social and political influences have shaped these observances.