Ramadan is not uniformly observed globally — the start date can vary by country or even be different mosque to mosque in the same city for a variety of reasons. But it all starts with a sighting of the crescent moon.

However, unlike other religious holidays, Ramadan doesn't start on the same day each year. This is because the Islamic calendar follows the moon's cycle. And what can be even more confusing is that different groups might give slightly different dates for when Ramadan starts,

The holy month of Ramadan will start on March 1 in Saudi Arabia with the sighting of a new crescent moon. In the Islamic calendar, a new month begins with the crescent moon, which is when the moon appears as a thin sliver.