Monday marked the first calendar day of Ramadan 2013, the holy month for Muslims around the world, who will fast and practice abstinence from dawn until sunset for 30 days. The annual event marks the anniversary of the Quran being revealed to the Prophet Muhammad.

Ramadan is held during the ninth month of the 12-month Islamic calendar, starting after the sighting of the new moon. The holy month lasts for 29 or 30 days, this year beginning on Monday, July 8, at sunset, or “rukyah,” when the moon is spotted, and going on until the next new moon appears, on Wednesday, Aug. 7. The month of fasting is celebrated by more than 1.5 billion Muslims around the world, including in the U.S., where there are nearly 2.6 million Muslims, according to the Pew Research Center.

This year, one of Britain’s top broadcasters, Channel 4, will broadcast the three-minute call to prayer at 3 a.m. on each day of Ramadan. The channel's act of “deliberate provocation” is designed to break the stigma for those who associate Islam with terrorism. While it has caused a bit of controversy for British citizens, assistant secretary-general of the Muslim Council of Britain Ibrahim Mogra told Voice of America that the move will make Muslims feel welcome in British society. “I think this will certainly help,” he said. “It is not going to dispel all the myths and misconceptions about Islam in one go. But every effort helps.”

The purpose of Ramadan is to focus on spirituality, praying more often and withholding any acts of violence during the fast. All Muslims around the world are expected to participate, with the exception of the elderly, sick and pregnant, by wishing each other "Ramadan Kareem" or "Ramadan Mubarak."

As one of the five pillars of Islam, Muslims are expected to refrain from food and drink and abstain from smoking and sex each day during the celebration from dawn to dusk. The breaking of the fast, or iftar, begins at dusk by eating dates. Some Muslims have slightly different variations and have broader definitions of practices during Ramadan.

Ramadan commences annually with a celebration called Eid al-Fitr, comprised of feasting and prayer. Ramadan ends with the three-day Eid al-Fitr festival, sometimes abbreviated as Eid, where many feast and join in Islamic prayer, known as salat, while saying "Allahu Akbar" or "God is Great.”