A prominent group of Muslim scholars has announced that Ramadan, the Islamic holy month of fasting, will begin on July 20.

The Fiqh Council of North America, a U.S.-based group affiliated with the Islamic Society of North America, made the announcement on Friday after using scientific calculations to determine July's new moon. The organization regularly makes rulings on Sharia, or Islamic law, such as its annual ruling on the dates of Ramadan.

The Islamic calendar follows a lunar cycle and the dates of Ramadan, the holiest Islamic month when Muslims fast during the daylight hours, change each year. While the Fiqh Council of North America is well-known among North American Muslims, its ruling on the beginning of the Islamic holy month is not binding nor followed by all Muslims.

Ramadan is the ninth month of the Islamic calendar and Muslims around the world frequently disagree on when it begins. Some Muslims will wait until they can see the new moon with their own eyes, while other Muslims will rely upon moon sightings by friends to know when they should start observing Ramadan. Other Muslims, regardless of what part of the world they live in, will follow the sighting of the new moon in Mecca, Saudi Arabia, which is Islam's holiest city.

During Ramadan, Muslims wake up before dawn for breakfast and abstain from food, water and sex during the day before breaking their fasts with group dinners at night. The days are punctuated by prayers, and Muslims try to read the Quran, their holy book, at least once in its entirety before the month's end. Mosques will also often organize community service activities.

In its announcement, the Islamic council also predicted a date for the end of Ramadan, which is marked by a festive holiday called Eid al-Fitr. That date, August 19, corresponds with the new moon and the Islamic month of Shawwal.

The organization is promoting a website, www.moonsighting.com, to help Muslims track when the new moon begins.