Saturday will be the 29th day of Ramadan for Saudi Arabia and the countries that started observing the fasting month on May 27.
These countries will be on the lookout for the Eid moon that evening. If sighted, the first day of Eid al-fitr will be observed on Sunday, June 25. Otherwise, it will be celebrated on Monday, June 26, in those countries.
Astronomers calculated that the new moon is expected on Saturday. Its visibility, however, depends on the meterological conditions.
On June 4, the moon is set to be visible with the naked eye in Peru, Equador, and islands in the Pacific Ocean.
It is expected to be visible with optical aids in Latin America, parts of the US, Africa, Saudi Arabia and Yemen.
African countries are also expected to celebrate the first day of Eid on Sunday, June 25.
Turkey, as well as Muslim communities in Australia, Europe, and North America (ISNA), are set to observe Eid al-Fitr from Sunday, based on the astronomical calculation that the new moon will be born on Saturday June 24.
Bangladesh, India and Pakistan started Ramadan on May 28 and therefore will be on the lookout for th eEid moon on Sunday, June 25.
On June 25, the moon is expected to be visibile with the naked eye all over the world.
At the International Hijri Calendar Unity Congress held in Istanbul last May, members of the Organisation of Islamic Cooperation voted in favour of adopting a unified lunar calendar.
However, local sighting continues to be the default policy in each country.
Last year, Eid al-Fitr was celebrated on July 6.