Why your prayer app and mosque disagree: Fajr, Isha and Asr by method

When a prayer app and a mosque timetable disagree, the large gaps are almost always at Fajr, Isha or Asr; Dhuhr and Maghrib rarely move by more than a few minutes. Three of the five times are set by convention. Fajr and Isha depend on how far below the horizon the sun has to be, which the common methods put anywhere from 12° to 20°. Asr depends on whether a shadow must reach one object-length or two. A printed timetable then adds precautionary minutes and its own rounding.

This post sets the methods side by side, prints what the angles cost in minutes, and shows the settings in PrayerTimes Pro, the studio's menu-bar prayer app for the Mac, which offers most of these methods and can be nudged by minutes towards a mosque's timetable. It does not say which method is correct; that belongs to scholars and to the community you pray with.

Three of the five times are a convention

The definitions on praytimes.org show where the room is. Dhuhr is "the time when the Sun begins to decline after reaching its zenith", and Maghrib, in the Sunni view, begins "once the Sun has completely set below the horizon". Both are events an almanac can time to the second.

Fajr is "the moment when the sky first begins to lighten at dawn", and Isha is "the time when complete darkness sets in, and no scattered twilight remains in the sky". Twilight fades gradually, so a calculation has to pick a depression angle: how many degrees below the horizon the sun sits when Fajr or Isha begins. Asr is a shadow length, and two schools define it differently.

The methods side by side

This is the table from praytimes.org, "Calculation Methods", with the regions it gives for each:

Method	Fajr	Isha	Maghrib	Midnight	Region the source names
Muslim World League (MWL)	18°	17°	sunset	sunset to sunrise	Europe, Far East, parts of US
ISNA	15°	15°	sunset	sunset to sunrise	North America
Egypt	19.5°	17.5°	sunset	sunset to sunrise	Africa, Syria, Lebanon, Malaysia
Makkah (Umm al-Qura)	18.5°	90 min after Maghrib, 120 in Ramadan	sunset	sunset to sunrise	Arabian Peninsula
Karachi	18°	18°	sunset	sunset to sunrise	Pakistan, Afghanistan, Bangladesh, India
Tehran	17.7°	14°	4.5°	sunset to Fajr	Iran, some Shia communities
Jafari	16°	14°	4°	sunset to Fajr	some Shia communities worldwide
France	12°	12°	sunset	sunset to sunrise	France
Russia	16°	15°	sunset	sunset to sunrise	Russia
Singapore	20°	18°	sunset	sunset to sunrise	Singapore

Not everyone accepts a fixed angle at all. The Moonsighting Committee writes that observations "have confirmed that it is not right to calculate Fajr & Isha, assuming any fixed degree (whether 18degrees or 15degrees) or any fixed minutes", and it uses functions of latitude and season instead (moonsighting.com).

Tables go out of date: Malaysia in 2019

On 20–21 November 2019, the 116th meeting of the Muzakarah committee of Malaysia's National Council for Islamic Religious Affairs (MKI) decided that Subuh, the dawn prayer, begins at a solar altitude of 18° below the horizon instead of the 20° used before. The Federal Territories' Syariah committee confirmed it on 2 December 2019, and the dawn time moved about 8 minutes later on average (Jabatan Mufti Wilayah Persekutuan, AL-KAFI #1638). The praytimes.org table still files Malaysia under Egypt's 19.5°. If your app's Malaysian times look 8 minutes early, this is the first thing to check. PrayerTimes' Malaysia (JAKIM) method uses 18°.

Two statements from the Fiqh Council of North America

For North America there are two published FCNA positions, and they differ. The Council's own site, citing its October 2017 general body meeting, says it "suggests using 15° for both Fajr and Isha in the USA and using 13° for both Fajr and Isha in Canada, throughout the year" (fiqhcouncil.org). An earlier statement, agreed at an FCNA meeting on 25 September 2011 and published by the International Astronomical Center in 2012, recommends Moonsighting.com's seasonal functions and adds that "if one wants to calculate Fajr & Isha based on degrees, one can opt to use 17.5° for Fajr and 15° for Isha'" (astronomycenter.net).

PrayerTimes' ISNA (North America) method uses 15° and 15°, and its Fiqh Council (Canada) method 13° and 13°. A mosque following the 2011 figures or Moonsighting.com needs a different setting; this post does not decide between them.

What a few degrees costs in minutes

I computed these with the calculation engine that ships in PrayerTimes 5.2.0 for 15 October 2026, in local clock time, with no corrections: Cairo at 30.0444°N, 31.2357°E, and London at 51.5074°N, 0.1278°W.

Method	Cairo Fajr	Cairo Isha	London Fajr	London Isha
Egypt (19.5° / 17.5°)	05:30	19:42	05:30	19:55
Umm al-Qura (18.5° / 90 min)	05:35	19:54	05:30	19:37
MWL (18° / 17°)	05:37	19:39	05:33	19:52
Karachi (18° / 18°)	05:37	19:44	05:33	19:58
ISNA (15° / 15°)	05:51	19:30	05:53	19:39
France (12° / 12°)	06:05	19:16	06:12	19:20

Sunrise that day is 06:57 in Cairo and 07:24 in London; Maghrib is 18:24 and 18:07.

The same three degrees between 18° and 15° cost 14 minutes at Fajr in Cairo and 20 in London, because further from the equator the sun sinks at a shallower slant. Umm al-Qura's fixed 90 minutes gives the latest Isha in Cairo and the second earliest in London, because an interval does not stretch with the twilight the way an angle does. And London's Egyptian Fajr is 05:30, not the 05:23 its 19.5° gives: at 51.5°N the app's Recommended high-latitude rule does not let Fajr fall earlier than the last seventh of the night, even in October. In June that rule takes over completely; Isha at 11pm covers it.

Asr: one shadow or two

praytimes.org gives the two positions plainly. The majority of schools, "Shafi'i, Maliki, Ja'fari, and Hanbali", hold that "Asr begins when the length of an object's shadow equals the object's own height plus its shadow length at noon". The Hanafi school holds that Asr begins "when the shadow is twice the length of the object plus its shadow length at noon" (praytimes.org). Those are the definitions; which one a person follows is a matter of their school, not of the app.

The method does not touch Asr: every method above gives 15:57 in Cairo and 15:31 in London. Only the shadow factor moves it, and by more than any angle does. By the same engine, the Hanafi Asr comes later by:

Date (2026)	Cairo	London
15 January	43 min	32 min
15 June	78 min	74 min
15 October	49 min	44 min

If your app's Asr is 40 minutes to more than an hour off your mosque's, the shadow factor is almost certainly the reason.

Maghrib and midnight are not the same everywhere

The Tehran and Jafari methods do not put Maghrib at sunset. praytimes.org explains that "the dominant Shia opinion holds that Maghrib prayer should not be performed until the redness in the eastern sky, visible after sunset, has passed overhead", modelled as an angle of 4° or 4.5°. In Cairo on 15 October that is 18:42 under Tehran and 18:39 under Jafari, against a sunset of 18:24. In London it is 18:31 and 18:28, against 18:07.

Midnight splits too. Astronomical midnight is halfway between sunset and sunrise, but "in Islamic jurisprudence, the legal midnight (the ending time for performing Isha prayer) is generally calculated as the midpoint between Sunset and Fajr" (praytimes.org). In Cairo that night, sunset to sunrise gives about 00:40, while sunset to the next Fajr gives 00:01 with MWL's Fajr and about 00:05 with Jafari's. Two apps can show midnights 35 minutes apart without either being broken. PrayerTimes' Show Islamic Midnight row measures from Maghrib to the next Fajr, so under Tehran or Jafari it lands a few minutes after the sunset-to-Fajr figure.

What a timetable adds on top

A mosque's timetable is a finished document, not raw geometry. praytimes.org gives Maghrib as sunset "with a precautionary delay of 1 to 3 minutes", and the FCNA page above reminds readers to consider "delaying the start of Fajr/Isha prayer by a few minutes to ensure that the time has really entered". Every timetable also rounds to whole minutes, so a one-minute disagreement can be nothing more than which way the two sides round.

PrayerTimes does not claim to match any official timetable to the minute, and open reports on its public tracker say where it does not. Issue #9 reports Riyadh one minute earlier than the official Umm al-Qura calendar. Issue #10 reports Dhuhr 5 minutes and Maghrib 4 minutes earlier than Morocco's Ministry of Habous timetable. Issue #11 reports sunrise 6 to 7 minutes later and Maghrib 1 to 2 minutes earlier than Jordan's Ministry of Awqaf timetable. All three were open on the day this was written.

From the studio: PrayerTimes Pro has a Time Correction screen that moves any one of Fajr, Sunrise, Dhuhr, Asr, Maghrib and Isha by whole minutes, up to 30 either way, and shows the calculated time beside the corrected one, so a timetable's margins can be matched prayer by prayer.

Before correcting anything, check which column you are comparing against. The iqamah is when the congregation stands, a gap after the prayer's start that the mosque chooses; an app's time is the start, so against an iqamah column it will always look wrong. In PrayerTimes the iqamah is a separate setting under Settings → Sounds, where, in the app's own words, you "set each gap to match your mosque", and its time shows beside each prayer.

Matching your mosque in PrayerTimes

Everything below is in Settings → Prayer Times → Calculation, with the labels as they appear in version 5.2.0:

• Method. On Automatic the app picks one by country: ISNA (North America) in the US, Fiqh Council (Canada) in Canada, Moonsighting Committee in the UK and Ireland, Egyptian General Authority in Egypt, Umm al-Qura in Saudi Arabia, Malaysia (JAKIM) in Malaysia, and the Muslim World League where it has no specific match. The row names the method Automatic currently means. Pick any of the twenty-six by hand instead; each name in the list carries its angles, such as "Fajr 18° · Isha 17°", to compare with your mosque's.
• Time Correction. The per-prayer minutes described above. Its footer says what it is for: "Adjust prayer times to match your local mosque."
• Hanafi Madhhab (for Asr). A switch; its subtitle reads "Asr falls later in the afternoon." It applies the two-shadow definition. With the Moonsighting Committee method it also moves Isha to the white twilight, which in London on 15 June 2026 is 23:45 instead of 22:38.
• Isha Ends At. First third of the night, or Islamic midnight.
• High Latitude Rule. Recommended, Middle of the Night, Seventh of the Night or Twilight Angle. Its subtitle says it "matters above about 48° latitude".

There is no setting for typing your own Fajr or Isha angle. If your mosque uses an angle that none of the twenty-six methods has, pick the nearest and close the gap with Time Correction, knowing the gap will drift a little with the seasons.

What an app should not decide for you

Which angle is right, and which shadow, is not settled on a settings screen. Some official bodies answer the practical question directly. The Iftaa Department of Jordan, asked about relying on prayer apps, answered that "in case there is a difference between these times and those offered by the apps, then a Muslim must follow the times issued by the official authorities in his country" (islamqa.org). Questions such as 15 or 18 degrees for the start of the fast are answered there by people qualified to answer them.

So start with your mosque. Ask which method, which Asr and which margins its timetable uses, set the same three in your app, and correct the remaining minutes against one week of the printed times. If you live far enough north for summer Isha to drift towards midnight, read Isha at 11pm next.