Predicted start dates for upcoming Islamic months based on your location
Enter a zip code or use "My Location" for calendar predictions
The Islamic calendar is based on moon visibility predictions that vary by location. Use the search bar above or click "My Location" to see predicted start dates for upcoming Islamic months.
The Islamic (Hijri) calendar is a purely lunar calendar consisting of 12 months that alternate between 29 and 30 days. Each month begins when the crescent moon (Hilal) is first sighted after a new moon conjunction. Because the lunar cycle averages 29.53 days, the Islamic year is approximately 354 days — about 11 days shorter than the Gregorian solar year. This means Islamic months migrate through the seasons over a 33-year cycle.
Unlike fixed calendars, the start of each Islamic month depends on actual moon visibility, which varies by geographic location. A crescent visible in one city may not yet be visible in another due to differences in latitude, longitude, altitude, and atmospheric conditions. This is why predicted start dates can differ by one day between regions.
For each upcoming Islamic month, we identify the new moon conjunction date and calculate Hilal visibility conditions at sunset on the 29th of the current Islamic month. Using NASA JPL ephemeris data and a machine learning model trained on 2,000+ historical observations, we predict whether the crescent will be visible — and therefore whether the new month begins that evening or the following day.
Predictions are location-specific. Enter your zip code or allow geolocation access to see start dates calibrated to your exact position and timezone.