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🌙 Moon Phase & Hilal (Crescent) Visibility

Moon phase, age, illumination, altitude/azimuth, elongation and moonset lag, next new moon (conjunction) and crescent visibility estimates using the Odeh and Yallop criteria.

How to use: Moon Phase & Hilal (Crescent) Visibility

Moon phase, age, illumination, altitude/azimuth, elongation and moonset lag, next new moon (conjunction) and crescent visibility estimates using the Odeh and Yallop criteria. Everything happens inside your browser on your own device. Your files, numbers and text are never uploaded, there are no accounts, cookies or trackers, and closing the tab removes the data.

Common uses

Checking whether the crescent may be visible tonight
Seeing the moon phase and age
Learning about astronomical visibility criteria

Step by step

Set your location and date.
See moon data at sunset.
Check the next conjunction and the visibility estimate for the following evenings.

Worked example

For example, on the evening after conjunction the tool shows moon age, moonset lag and Odeh/Yallop estimates. These are predictions; official sighting decisions come from authorities.

Tips for better results

Calendars and astronomical calculations can differ from local announcements by a day or a few minutes. Use the results for planning, and follow your local authority or mosque for official dates and times. The page is designed for phones first, so it works on a 375-pixel screen as well as on a desktop.

Good to know

Hijri dates in this site use the Umm al-Qura calendar, which is the official calendar in Saudi Arabia and is calculated in advance. In other countries the month can begin a day earlier or later, depending on a local moon sighting. Times are shown in your device’s time zone, so check that your phone’s clock and time zone are set correctly when you travel.

Why a browser-based tool?

Many online tools upload whatever you give them to a remote server, process it there and send it back. That is slower on a weak mobile connection and means a copy of your document, photo or figures sits on someone else’s computer. Free Adawat works differently: the code is downloaded once, then the work happens on your phone or computer. That keeps personal papers such as passports, visas, salary slips and contracts private, and it also means there is no queue, no file count limit and no waiting for a download link.

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FAQ

Is this an official moon sighting?

No. It is an astronomical estimate, not an official sighting; follow your local authority.

What are the Odeh and Yallop criteria?

Scientific criteria comparing the moon's altitude above the sun (ARCV) with crescent width (W) to estimate naked-eye or optical visibility.

Is Moon Phase & Hilal (Crescent) Visibility free?

Yes. It is completely free, with no sign-up, no watermark and no daily limit. The only limit is your device memory for very large files.

Are my files or data uploaded?

No. All processing happens in your browser on your device. Nothing you enter or select is sent to a server.

Does it work on a phone?

Yes. It works in modern mobile browsers on Android and iPhone, and on tablets and computers.

Does it work without internet?

Once the page has fully loaded, the tool runs on your device, so it keeps working if the connection drops. Pages you have visited before can often open offline too.

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