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Prayer times and the adhan on your PC: calculation methods explained

Why prayer times differ between apps, which calculation method your country uses (with the Fajr and Isha angles), what Hanafi Asr changes, and how to get the adhan on a Windows PC or Mac without installing software.

Updated · 3 min read

If your phone app, the mosque timetable and a website all disagree on Fajr, none of them is broken. They’re using different calculation methods. Knowing which method your community follows is the first step to times you can trust, on any device.

In short

  • Fajr and Isha depend on a sun angle that varies by authority, from 12° to 20°.
  • Hanafi Asr is later than standard Asr; pick the one your mosque uses.
  • On a computer, a browser extension can show the times and play the adhan without installing software.

Calculation methods by region

Each method fixes how far below the horizon the sun must be for Fajr to begin and Isha to begin. Some use a fixed interval after Maghrib for Isha instead.

MethodFajrIshaCommonly used in
Muslim World League18°17°Europe, the Far East, parts of America
Islamic Society of North America15°15°North America
Egyptian General Authority of Survey19.5°17.5°Africa, Syria, Lebanon, Malaysia
Umm al-Qura, Makkah18.5°90 min after MaghribSaudi Arabia
University of Islamic Sciences, Karachi18°18°Pakistan, India, Bangladesh, Afghanistan
UAE (General Authority of Islamic Affairs)18.2°18.2°United Arab Emirates
Gulf region19.5°90 min after MaghribGulf states
Kuwait18°17.5°Kuwait
Qatar18°90 min after MaghribQatar
Majlis Ugama Islam Singapura20°18°Singapore, Malaysia, Indonesia
Diyanet İşleri Başkanlığı18°17°Turkey
UOIF12°12°France
Spiritual Administration of Muslims of Russia16°15°Russia
Institute of Geophysics, Tehran17.7°14°Iran
Shia Ithna Ashari (Jafari)16°14°Shia communities
Moonsighting Committee Worldwide18°18°Worldwide

Rule of thumb: when in doubt, use the method your local mosque prints on its timetable, and compare a week of times.

Asr: standard or Hanafi

Standard Asr begins when the shadow of an object equals its length (plus its shadow at noon). The Hanafi school waits until the shadow is twice the length, which puts Asr later in the afternoon. Most of South Asia and Turkey follow the Hanafi time; much of the Arab world, Southeast Asia and Africa follow the standard time.

Far north and far south

In summer at high latitudes the sun may not sink 15° to 18° below the horizon at all, so Isha and Fajr have no astronomical time. Methods handle this with a rule: split the night in half, use one-seventh of the night, or scale by the angle. If you live in the UK, Scandinavia or Canada, it’s worth choosing one deliberately.

Your options on a computer

OptionGoodLess good
Phone appAccurate, plays the adhan anywhereEasy to miss when the phone is in a bag during work
Desktop softwareRuns without a browserAnother program to install and update; often Windows only
Prayer-times websiteNothing to installNo reminder unless the tab stays open
Browser extensionShows times on every new tab; reminders even with no tab openNeeds Chrome, Edge, Brave or Firefox running

Set up the adhan in Pax

  1. Add Pax to Chrome, Edge or Brave and choose Islam during setup.
  2. Allow your location, or type your city. Pax suggests the usual method for your country.
  3. In Settings › Faith, confirm the method and the Asr school, and pick a high-latitude rule if you need one.
  4. Turn on Prayer reminders, choose at the prayer or a few minutes before, and set Sound to Adhan, Chime or Silent.

Times are calculated on your device, and the Hijri date (adjustable by a day for local moon sighting) and the Qibla bearing appear beside them.

Questions people ask

Why do two prayer apps show different Fajr times?

They use different calculation methods. Fajr and Isha are set by how far the sun is below the horizon, and authorities disagree on the angle, from 12° to 20°. A larger angle gives an earlier Fajr and a later Isha.

What is the difference between Hanafi and standard Asr?

Standard (Shafi’i, Maliki, Hanbali) Asr begins when an object’s shadow equals its length plus its noon shadow. Hanafi Asr waits until the shadow is twice the length, so it is later, often by around an hour.

Can I hear the adhan on my computer without an app?

Yes. Pax, a free browser extension, can play the adhan at each prayer, or a few minutes before, on Windows, Mac, Linux and ChromeOS.

What happens in summer in the far north?

Above about 48° latitude the sky may never get dark enough for the usual Isha angle. High-latitude rules (middle of the night, one-seventh of the night, or angle-based) set a reasonable time instead.

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