Watch the Moon from any city, and know when the new crescent can be seen

How to use this page

Choose your town with the place button at the top. The sky shows the real position of the Sun and the Moon from there, in your own time zone, and you can play it forward or back to any date. Below the sky, each evening after the new moon gets a card with the verdict of three methods, the time the Sun and the Moon set, and a button that plays that sunset so you can watch where the young crescent will be. The folded box above the cards shows the previous new crescent, the one that began the current Hijri month. The world map shows where the crescent can be seen on each evening, and the converter turns any Gregorian date into its Umm al-Qura Hijri date and back.

Why do countries start the month on different days?

Three different approaches are in use, and they can give different answers on the same evening.

Sighting. The month begins when the new crescent is actually seen after sunset. Some authorities accept only naked-eye reports; others also accept sightings made with binoculars or a telescope. That single choice often explains a one-day difference.

Astronomical visibility. Criteria such as Odeh (2006), used by the International Astronomy Center, and Yallop (1997), used by HM Nautical Almanac Office, use the Moon’s height above the Sun at sunset and the thickness of the crescent to predict where a sighting is possible. They assume a clear sky; dust, humidity and cloud can make a predicted sighting fail.

Calculated calendar. Saudi Arabia’s Umm al-Qura calendar starts a month when, on the 29th, the new moon happens before sunset and the Moon sets after the Sun at Mecca. It does not require the crescent to be visible, so it can begin a day before any sighting is possible.

The Moon’s age, or how long it stays up after sunset, is not reliable on its own, because visibility depends on how far the Moon is from the Sun and how high it is when the sky becomes dark enough. On the evening of 7 February 2027, for example, the Moon sets about 45 minutes after the Sun in Mecca and is only possible by eye in a very clear sky, while in New York it stays up for 72 minutes and is easy to see.

The next twelve Hijri months

The new moon (conjunction) for each month, the day the month begins in the Umm al-Qura calendar, and the first evening the crescent is likely to be seen by eye from Mecca by the International Astronomy Center criterion. Where the month begins on the same day as that evening, the calendar starts before the crescent can be seen.

Planning for Ramadan? Read where the Ramadan 2027 crescent can be seen on 7 February, city by city.

Hijri and Gregorian dates

The Umm al-Qura calendar is the official calendar of Saudi Arabia. Its months have 29 or 30 days and its year 354 or 355, about 11 days shorter than the Gregorian year, so Islamic dates move earlier through the seasons each year. The converter above uses the same calendar and offers only days that exist, so a 29-day month has no 30th.

Questions people ask

More: how we calculate · International Astronomy Center: the Saudi calendar rules · IAC monthly crescent reports