Predicted dates for major Islamic events based on crescent moon visibility calculations. Select an event and year to see city-by-city predictions.
The Islamic (Hijri) calendar is a purely lunar calendar consisting of 12 months of 29 or 30 days. Each month begins with the sighting of the new crescent moon (Hilal) after sunset. Because the lunar year is approximately 354 days, Islamic events shift earlier by about 10-11 days each Gregorian year.
Our predictions use NASA JPL DE421 ephemeris data to calculate precise astronomical conditions — including moonset lag, moon age, altitude, elongation, and illumination — at each location. A machine learning model trained on over 2,000 historical observations then produces a confidence score for crescent visibility, allowing us to predict when each Islamic month is most likely to begin.