The Islamic calendar is lunar, and each month begins with the sighting of the new crescent moon. Some communities follow a calculated calendar; others wait for the moon to be sighted locally, which can fall a day later or earlier. Neither is “wrong”. It depends on the position your mosque follows.

By default this app uses the standard calculation. If your community differs, you can shift your dates by a day with the setting above.

The Day of Arafah and Eid al-Adha are the exception. These are tied to the actual Hajj pilgrimage in Makkah, the standing at Arafah happens on one specific day for the entire world. For that reason, these dates always follow Saudi Arabia regardless of your setting, in line with the majority view. Adjusting them locally would not reflect when Hajj is actually performed.

Dates are calculated, not based on real-time sightings. Always confirm with your local mosque close to the time.