Crescent visibility

Moon Sighting — Crescent Visibility

Will the new crescent (hilāl) be visible from your location this evening? A forecast of the month’s start from the sun & moon’s positions and the Odeh visibility criterion — computed in your browser. It does not replace an actual sighting.

Where & when

Or pick a city Evening of

The sunset to evaluate — usually the 29th of the lunar month.

Calculated in your browser

Your figures are never sent to any server — every calculation runs on your device.

A forecast, not a decree

The start of the month is established by actual sighting and the ruling of your local authority — calculators differ and even the zones are probabilistic. Use this to anticipate, not to decide.

Method & sources

Sun & moon positions follow Meeus’ Astronomical Algorithms (ch. 25, 47); the new moon from ch. 49; sunset from our prayer engine. The visibility verdict uses Mohammad Odeh’s criterion (2006), as used by the Islamic Crescent Observation Project (ICOP).

ICOP — Odeh visibility criterion↗

Mohammad Odeh’s 2006 criterion (arc of vision + crescent width → zones A–D), the standard the Islamic Crescent Observation Project applies.

J. Meeus — Astronomical Algorithms↗

Sun (ch. 25), moon (ch. 47) positions and the new-moon instant (ch. 49) — cross-checked against the astronomia library.