Ramadan, Arabic Ramaḍān, in Islam, the ninth month of the Muslim calendar and the holy month of fasting. It begins and ends with the appearance of the new moon.

Islamic tradition states that on the night of 27 Ramadan—the “Night of Power” (Laylat al-Qadr)—God revealed to the Prophet Muhammad the Qurʾān, Islam’s holy book, “as a guidance for the people.” For Muslims Ramadan is a period of introspection, communal prayer (ṣalāt) in the mosque, and reading of the Qurʾān. God forgives the past sins of those who observe the holy month with fasting, prayer, and faithful intention.

Ramadan, however, is less a period of atonement than it is a time for Muslims to practice self-restraint, in keeping with ṣawm (Arabic: “to refrain”), one of the Pillars of Islam (the five basic tenets of the Muslim religion). Although ṣawm is most commonly understood as the obligation to fast during Ramadan, it is more broadly interpreted as the obligation to refrain between dawn and dusk from food, drink, sexual activity, and all forms of immoral behaviour, including impure or unkind thoughts. Thus, false words or bad deeds or intentions are as destructive of a fast as is eating or drinking.