Hundreds of millions of Muslims began the fasting month of Ramadan on Saturday. In Saudi Arabia, the United Arab Emirates and Indonesia, March 1 has been declared as the first day of fasting. The start is based on the sighting of the new moon crescent and can therefore vary depending on the country.

The Muslim holiday of Ramadan starts tonight, Feb. 28, and lasts until March 29. The monthlong observance of Ramadan is a period of introspection, communal prayer and reading the Qurʾān. According to Islam, those who observe the holy month of Ramadan with fasting, prayer and faithful intention are forgiven by God for their past sins.

Ramadan is a time of togetherness for Muslims, as they fill mosques for hours of prayer and share large, lavish meals with family, friends and neighbors after days of dawn-to-dusk fasting.