The moon's orbit lasts 29.25 days on average.

The sighting of the new crescent at sunset marks the beginning of a month. On the 29th of the month, this is done.

The month ends if the moon is seen, and a new month begins.

If the moon cannot be seen, the month is finished by completing 30 days.

A moon sighting is not required on the 30th day because a lunar month is not longer than 30 days.

This means that a lunar month is either 29 or 30 days long based on the sighting of the crescent.

Ramadan 2022 is starting on 2nd April, Saturday.