CAIRO (AP) — Religious authorities in most Middle Eastern countries have declared that Friday will be the start of the holy month of Ramadan, a period devoted to dawn-to-dusk fasting, prayers and good deeds.

Official statements issued Thursday in Egypt, Saudi Arabia, Lebanon, Jordan, Qatar and Yemen said the holy month will start the following day. Syria however said the holy month will begin Saturday.

Ramadan's start is calculated based on the sighting of the new moon, which marks the beginning of the Muslim lunar month. Some countries use astronomical calculations and observatories, while others rely on the naked eye alone, leading sometimes to different starting times in the Middle East.

Political differences and religious disputes between Sunni- and Shiite-majority countries in the region also sometimes play a role in different starting dates.