Religious authorities in much of the Middle East declared that Monday will be start of the holy month of Ramadan, when observant Muslims fast from dawn to dusk.
Official statements were issued late Saturday in Yemen, Saudi Arabia, the United Arab Emirates, Egypt and the Palestinian territories. Religious authorities in Syria, Qatar and Kuwait agreed.
Ramadan starts the day after the sighting of the crescent moon that marks the beginning of a new lunar month. Some countries use astronomical calculations and observatories, while others rely on the naked eye alone, leading sometimes to different starting times.
Libya, for example, will begin the holy period on Sunday. The state-run Libyan news agency reported that religious officials there had already spotted the first tiny sliver of moon.
In Shiite Iran, newspapers reported that Ramadan would likely to start Tuesday.
In Iraq, some Shiites will follow the Iranian start, while Sunnis will begin on Monday, like Saudi Arabia.
Ramadan can last either 29 or 30 days, depending on when the first moon of the next lunar month is sighted. During the month, Muslims are expected to abstain during daylight hours from food, drink, smoking and sex to focus on spiritual introspection.
The start of the holy month has also caused some clock confusion in the region, as some countries went off daylight saving time to reduce the daylight fasting hours in soaring summer temperatures.
Ramadan begins around 11 days earlier each year. Currently, that brings it more and more into the long, hot days of summer, AP reported.