Saudi Arabia and most Arab countries will celebrate Eid al-Fitr, which marks the end of the Muslim fasting month of Ramadan, on Monday.
In a statement, the Saudi Royal Court said the new moon of Shawwal, the 10th month in the Islamic lunar calendar, was not born on Saturday, April 30.
"Hence, Sunday, May 1 will be the last day of Ramadan and Eid al-Fitr will be on Monday, May 2," it added.
Religious authorities in Qatar, the United Arab Emirates, Kuwait, Bahrain and Yemen announced the start of Eid al-Fitr on Monday.
The Islamic holiday will also be celebrated on Monday in Egypt, Sudan, Libya, Lebanon, Syria and Palestine.
Sunni Muslims in Iraq will also celebrate the start of Eid al-Fitr on Monday.
Meanwhile, Oman, Jordan and Iraq's Shias will sight the new moon on Shawwal on Sunday to determine the start of Eid al-Fitr.
