Religious authorities in most Middle Eastern countries have said that July 20 will mark the start of the holy month of Ramadan, a period devoted to dawn-to-dusk fasting, prayers, and good deeds.
Official statements issued on July 19 in Algeria, Egypt, Saudi Arabia, Lebanon, Jordan, Kuwait, Qatar, Tunisia, and Yemen said the holy month would start the following day.
In Oman and Syria, as well as for Iraq's Sunni Muslims and in non-Arab Iran, it will start on July 21.
The beginning of Ramadan is calculated based on the sighting of the new moon, which marks the start of the Muslim lunar month.
Countries use different astronomical calculations, which sometimes leads to different starting dates in the Middle East.
Religious disputes between Sunni- and Shi'ite-majority countries in the region also sometimes play a role in different starting times.