Prayer Time Calculation Methods: MWL, ISNA, Umm al-Qura

A prayer time calculation method is a named set of rules that turns the Sun's position into a daily timetable. Every method starts from the same astronomical sunrise, solar noon and sunset. They differ in three places: the Fajr angle, the Isha rule (an angle or a fixed number of minutes after Maghrib), and small built-in minute offsets. In London on 9 November 2026, those differences spread Fajr across 32 minutes (05:00 to 05:32) and Isha across 27 minutes (17:49 to 18:16), while Asr stayed within four minutes.

Key Takeaways

• Most methods differ only in Fajr and Isha. A few also shift Dhuhr, Asr, Maghrib or sunrise by a set number of minutes.
• Umm al-Qura and Qatar set Isha 90 minutes after Maghrib instead of using an angle, and the Moonsighting Committee replaces the fixed angle with a seasonal rule.
• The adhan library's Umm al-Qura, Singapore and Turkey presets matched the official Makkah, Singapore and Istanbul timetables to within two minutes in our checks for November 2026.
• No method is "the correct one". Use the method your local mosque or religious authority follows.

What a calculation method contains

The religious texts describe Fajr and Isha by what is seen in the sky: true dawn spreading across the horizon, and the evening glow fading. Software cannot see the sky, so it uses the Sun's depth below the horizon as a stand-in. The US Naval Observatory defines astronomical twilight as the moment the Sun's centre is 18 degrees below the horizon. Several methods use exactly that figure, while others go shallower or deeper. Why the angles differ, and what dawn observations have found, is covered in Fajr and Isha twilight angles.

A full method needs more than two angles, though. In the open-source adhan library's calculation parameters, a method can also set:

• a fixed Isha interval in minutes after Maghrib, used instead of an Isha angle;
• a Maghrib angle, so that Maghrib waits until the Sun is a few degrees below the horizon rather than at sunset;
• method adjustments, a set number of minutes added to or taken from individual times;
• a rounding rule, either to the nearest minute or always up;
• a fallback high-latitude rule for nights when the Sun never sinks to the Fajr or Isha angle.

The Asr rule (shadow factor 1 or 2) is a separate setting from the method, so it is left out of the tables below. The Sun-position steps that turn these numbers into clock times are covered in how prayer times are calculated.

The methods side by side

This table lists every preset in the adhan library (version 4.4.3), the library this site uses, with the values read from its CalculationMethod source file. The "Where adhan suggests it" column repeats the library's own notes. It is not a survey of which countries use which method.

Three patterns stand out. ISNA's 15° gives the latest Fajr and one of the earlier Isha times. The Egyptian and Singapore presets use the deepest Fajr angles, so their Fajr comes earliest. Umm al-Qura and Qatar do not use an Isha angle at all, so their Isha is always 90 minutes after Maghrib, in any season and at any latitude.

The library's notes also flag a Ramadan rule for Umm al-Qura: its methods guide says users "should add a +30 minute custom adjustment for Isha during Ramadan". The preset does not do this by itself.

One city, one date, every method

To see what the parameters do in practice, here are the adhan results for central London (51.51° N, 0.13° W) on Monday 9 November 2026 (29 Jumada al-Awwal 1448). London is on GMT that day. Times were calculated with the open-source adhan library, version 4.4.3, using each preset unchanged, the standard Asr rule (shadow factor 1) and the library's default high-latitude rule, which does not alter any of these times on this date.

Reading the table

• Fajr follows the angle. The fixed 18° methods all give 05:13 (the Moonsighting Committee, below, works differently). Each deeper preset is earlier (Dubai 18.2° at 05:11, Umm al-Qura 18.5° at 05:09, Egyptian 19.5° at 05:03, Singapore 20° at 05:00), and ISNA's 15° is 19 minutes later at 05:32.
• Isha splits into angle and interval methods. Umm al-Qura and Qatar both show 17:50, which is 90 minutes after the unrounded sunset of 16:19:59. The angle methods range from 17:49 (Tehran, 14°) to 18:16 (Dubai and Singapore).
• The Moonsighting Committee is the outlier. It nominally uses 18°, yet its Fajr (05:30) is 17 minutes later than the other 18° methods and its Isha (17:49) is 26 minutes earlier than Karachi's. The seasonal rule, not the angle, sets both times here.
• Offsets move the "fixed" times. Sunrise, Dhuhr, Asr and Maghrib match for most methods. Turkey, Dubai and the Moonsighting Committee differ because of their built-in minutes, and Tehran's Maghrib comes 26 minutes after sunset because it waits for the Sun to reach 4.5° below the horizon.
• One-minute gaps come from Dhuhr adjustments and rounding. Kuwait, Qatar, Umm al-Qura and Tehran show Dhuhr at 11:44 because they add no minute; the Singapore preset rounds every time up, so its sunrise and Asr are a minute later.

On a summer date the spread would look different. Near the June solstice, London never reaches 18° below the horizon, and the high-latitude fallback rule, not the angle, decides Fajr and Isha.

How the presets compare with official timetables

A library preset is a reconstruction. Where an authority publishes its own timetable, the fairest check is to compare a computed day against it.

Umm al-Qura: Makkah

The official Umm al-Qura calendar prayer times page gave these times for Makkah on Tuesday 10 November 2026 (30 Jumada al-Awwal 1448): Fajr 05:11, sunrise 06:28, Dhuhr 12:05, Asr 15:17, Maghrib 17:41, Isha 19:11. The adhan Umm al-Qura preset, for central Makkah (21.42° N, 39.83° E), gave 05:10, 06:29, 12:05, 15:17, 17:40 and 19:10. Every time is within one minute, and the official Isha is exactly 90 minutes after the official Maghrib. The official page says its times follow "Umm Al-Qura calendar standards" but does not publish the angles, so this check confirms the outcome rather than the exact parameters.

Singapore: MUIS

The Islamic Religious Council of Singapore (MUIS) publishes its Muslim Prayer Timetable 2026 on the government's open-data portal. For Monday 9 November 2026 it lists Subuh 05:27, Syuruk 06:47, Zohor 12:50, Asar 16:11, Maghrib 18:51 and Isyak 20:03. The adhan Singapore preset, for central Singapore (1.35° N, 103.82° E), gives the same six times to the minute. The round-up setting matters: with ordinary rounding, Fajr, Maghrib and Isha each come out one minute earlier.

Malaysia: a change since the preset was written

The adhan notes still list Malaysia under the 20° Singapore preset, but Malaysia changed its Subuh parameter. A Kedah State Mufti Department fatwa notice (archived copy) records that the national Muzakarah committee, at its 116th meeting in November 2019, adopted a Sun altitude of 18° below the horizon for the start of Subuh. The notice says moving from 20° to 18° makes Subuh about 8 minutes later. Users in Malaysia should not assume the Singapore preset matches their state's timetable.

Turkey: Diyanet

Diyanet's official prayer times for Istanbul list, for 9 November 2026, imsak 06:10, sunrise 07:37, Dhuhr 12:53, Asr 15:34, Maghrib 17:59 and Isha 19:21. The adhan Turkey preset, for central Istanbul (41.01° N, 28.98° E), gives 06:10, 07:37, 12:53, 15:32, 17:58 and 19:20. That is within two minutes, consistent with the library describing the preset as an approximation that is "less accurate outside the region of Turkey".

Moonsighting Committee: the method's own statement

The Moonsighting Committee Worldwide explains how it calculates prayer times. It treats true dawn and the evening twilight as "functions of latitude and seasons" rather than a single fixed angle. It says those formulas hold up to 55° latitude, with a one-seventh-of-the-night rule used further from the equator. It also offers red or white evening twilight for Isha according to school, with a "general" option. The page describes that option as white twilight in summer and red in winter, but the same paragraph says the site itself uses red twilight in summer and white in winter, and the adhan code behaves the second way: its "general" curve matches white twilight at the winter solstice and comes close to red twilight in summer. The same page sets Dhuhr 5 minutes after solar noon and Sunni Maghrib 3 minutes after calculated sunset, which matches the +5 and +3 minute offsets in the adhan preset. In the London example, switching adhan's twilight option from general to red moves Isha from 17:49 to 17:27, and switching to white moves it to 17:51.

Methods without a published statement we could check

For the Muslim World League, ISNA, the Egyptian General Authority of Survey, Karachi, Kuwait, Qatar, Dubai and Tehran presets, we did not find a current statement or timetable from the named body that sets out its parameters. The values in the table are those used by the adhan library and repeated in many other prayer-time programs. Treat them as the software convention for each name, and check a local timetable published under that name before relying on it.

Choosing a method for your timetable

Which method to follow is a religious decision as much as a technical one. Scholars and councils have reached different conclusions about when true dawn and nightfall occur, and those conclusions are what the angles encode. Ask your local mosque or the religious authority you follow which method or timetable it uses, then set your app to match it.

Two practical points help:

1. Match the method, then compare the minutes. If a mosque timetable and an app still differ by one to three minutes after you choose the same method, built-in offsets and rounding are the likely reason. Larger gaps usually mean a different method or a different location.
2. Check again in summer if you live far from the equator. At high latitudes the fallback rule, not the method's angle, may set Fajr and Isha for weeks at a time.

If two apps disagree and you want a step-by-step way to find out why, our sister site Everyday Muslim has a checklist on why two prayer apps can show different times.

Compare the methods for your own city

The daily prayer times page lets you choose any of the twelve methods above, plus the Hanafi or standard Asr rule and a high-latitude rule, and see the timetable for your location. Change one setting at a time and watch which rows move: a change of method should move mainly Fajr and Isha. For cities in America, the United States prayer times pages list timetables by state and city. Calculated times are a planning aid; your local mosque's announced times take precedence.