Why do prayer times differ from one app to another?
When two apps show different prayer times for the same city, the cause is almost always the calculation method. Fajr and Isha depend on how far the sun sits below the horizon, and that angle varies between authorities. Türkiye’s Presidency of Religious Affairs (Diyanet) also adds a few safety minutes to some prayers, and there are two rules for Asr. Together these settings can move a single prayer by more than half an hour.
In this note we show where the gap comes from, using a real day in İstanbul, and add what we learnt while building the prayer times in Mümin 360. We give no religious ruling here. For questions of fiqh we point to the pages of Diyanet’s High Council of Religious Affairs.
How are prayer times calculated?
Prayer times are worked out from the sun’s position in the sky. Diyanet’s High Council of Religious Affairs takes the latitude and longitude of each settlement, finds where the sun stands relative to the horizon on each day, and sets the times from those positions according to the criteria of fiqh.
Each of the six times is tied to a different moment of the sun:
- Fajr (imsak): the first light of dawn, while the sun is still well below the horizon.
- Sunrise.
- Dhuhr: just after the sun reaches its highest point.
- Asr: when an object’s shadow reaches a set length.
- Maghrib: sunset.
- Isha: when the red glow of dusk has gone.
Authorities barely disagree on sunrise, sunset and noon. The differences gather at Fajr, Isha and Asr — and then there are the safety minutes.
Why does the Fajr and Isha angle matter so much?
Fajr and Isha are set by how many degrees the sun is below the horizon. The larger the angle, the earlier Fajr and the later Isha. Authorities have chosen different angles.
According to Diyanet’s statement of 17 July 2013, the Presidency’s calendars use 18° for Fajr and 17° for Isha. The same statement explains that a commission set up in 1949 had adopted 19° for Fajr, and that the Presidency moved to 18° in 1982. It also records an average gap of −0.8 ± 3.5 minutes between the calendar’s Fajr and the observed whitening of the sky.
The angles of the most widely used methods:
| Method | Fajr angle | Isha |
|---|---|---|
| Diyanet (Türkiye) | 18° | 17° |
| Muslim World League (MWL) | 18° | 17° |
| ISNA (Islamic Society of North America) | 15° | 15° |
| Umm al-Qura (Makkah) | 18.5° | 90 min after Maghrib, 120 min in Ramadan |
| Egyptian General Authority of Survey | 19.5° | 17.5° |
The values other than Diyanet’s come from the PrayTimes.org comparison of methods. Diyanet and MWL share the same angles, so whatever separates them comes from the safety minutes.
What are safety minutes and how do they shift the times?
Safety minutes (temkin in Turkish) are a small margin added to a calculated time. They absorb the slight difference between the coordinate used in the calculation and the spot where a person actually stands. Diyanet’s temkin page sets out the current practice:
| Prayer | Diyanet margin |
|---|---|
| Fajr | None |
| Sunrise | 7 minutes before astronomical sunrise |
| Dhuhr | 5 minutes after the sun’s highest point |
| Asr | 4 minutes |
| Maghrib | 7 minutes after astronomical sunset |
| Isha | None |
The same page notes that these margins were once applied more generously than needed. A 1982 decision of the High Council made them moderate, and that decision has applied since 1983.
Many apps using MWL, ISNA or Umm al-Qura add no margin at all. Maghrib then appears 7 minutes earlier than in the Diyanet calendar — a gap people notice at once when breaking the fast.
Why can Asr differ by more than half an hour?
There are two rules for Asr, and the gap between them can exceed thirty minutes depending on the season. Under the first, Asr begins when an object’s shadow equals its own length (plus its shadow at noon). Under the second, it begins when the shadow reaches twice the object’s length.
According to the High Council’s note on the two Asr times, the Diyanet calendar sets Asr by the first rule. The second rests on the view of Imam Abu Hanifa.
This is where a common mix-up happens. Many apps label the Asr setting “Hanafi” and “Shafi’i”. A Turkish user who picks “Hanafi” because they follow the Hanafi school will see Asr by the second rule — noticeably later than in the Diyanet calendar. Anyone who wants the app to match the Diyanet calendar should choose the single-shadow rule.
Same day, same city: how big are the gaps?
To make the gap concrete, we set İstanbul’s times for 8 November 2026 side by side. The Diyanet column is taken from Diyanet’s İstanbul prayer times page. We calculated the other columns ourselves from the same coordinate. When we ran our own calculation with the Diyanet method, it matched the official table to within one minute.
| Prayer | Diyanet (official) | MWL, no margins | ISNA | Umm al-Qura | “Hanafi” Asr setting |
|---|---|---|---|---|---|
| Fajr | 06:09 | 06:09 | 06:25 | 06:07 | 06:09 |
| Sunrise | 07:36 | 07:43 | 07:43 | 07:43 | 07:43 |
| Dhuhr | 12:53 | 12:48 | 12:48 | 12:48 | 12:48 |
| Asr | 15:34 | 15:30 | 15:30 | 15:30 | 16:11 |
| Maghrib | 18:00 | 17:53 | 17:53 | 17:53 | 17:53 |
| Isha | 19:21 | 19:21 | 19:10 | 19:23 | 19:21 |
Three things stand out:
- ISNA moves Fajr the most. Its 15° angle puts Fajr 16 minutes later. The gap grows in summer: by the same calculation, ISNA’s Fajr in İstanbul on 21 June comes 27 minutes after Diyanet’s.
- The 7 minutes at sunrise and Maghrib are the safety margin. Even MWL, with Diyanet’s angles, shows Maghrib at 17:53 rather than 18:00.
- The biggest Asr gap is a setting. The “Hanafi” option shows Asr 37 minutes later than Diyanet.
What else causes a difference?
Even with the right method, a few minutes can remain. Most of them come down to location.
- City centre or district? Diyanet publishes times by district. Its comparison page notes that noon in Tekirdağ and Adana differs by about 31 minutes all year. Even within one province, the eastern and western edges can be a few minutes apart.
- Device location or chosen city? An app using the phone’s location calculates for where you are. A city picked by hand uses that city’s central coordinate.
- Rounding. One app rounds the seconds down, another up, and a one-minute gap appears.
- Stale data. An offline app working from an old table or the wrong time zone drifts further.
How do you check your app’s settings?
You can check in five minutes whether your app matches the Diyanet calendar:
- Open Diyanet’s prayer times page and choose your province and district. Cities abroad are listed too.
- Choose the same place in your app, or allow location access.
- Compare the six times. If none is more than a minute out, the setting is right.
- If only Fajr and Isha differ, look at the app’s angle setting.
- If sunrise and Maghrib differ by 7 minutes, the app adds no safety margin.
- If Asr is more than half an hour late, switch the Asr setting to the single-shadow rule (often labelled “Shafi’i”, “standard” or “first Asr”).
How does Mümin 360 show prayer times?
In Türkiye, Mümin 360 takes its times from the data Diyanet publishes, so it shows the official calendar rather than calculating its own. Abroad, it calculates with the Diyanet method by default, and users who want to follow the method of the country they live in can choose MWL, ISNA or Umm al-Qura instead. Without a connection, the times are calculated on the phone.
The checks in this note apply to us as well. If you see a time in the app that looks wrong, please write to us. We explain what we deliberately leave out of Mümin 360 in what we leave out of a prayer app, and why keeping data on the phone matters in what is a local-first app.
Frequently asked questions
Which prayer time is correct?
This is a question of method and scholarly judgement; there is no single correct minute. In Türkiye the official calendar is the one published by the Presidency of Religious Affairs. Abroad, a good starting point is to ask which calendar your local mosque follows.
If Diyanet and MWL use the same angles, where does the gap come from?
From the safety margins and the Asr setting. Diyanet sets sunrise 7 minutes early and Maghrib 7 minutes late, and adds 5 minutes to Dhuhr and 4 to Asr. Most apps working with MWL add none of these.
Why isn’t the dawn call to prayer read at Fajr time?
According to Diyanet’s note on the dawn adhan, in Türkiye the dawn adhan is read at the moment of Fajr during Ramadan. Outside Ramadan it is read roughly an hour before sunrise. So outside Ramadan, the adhan and the calendar’s Fajr time do not coincide.
Which time should I follow for breaking the fast?
In the Diyanet calendar, Maghrib is astronomical sunset plus a 7-minute margin. An app without that margin may show Maghrib a few minutes early. Questions of fiqh on this are best put to the High Council of Religious Affairs or your local imam.
Mümin 360 - Namaz Kıble Zikir is free on the App Store: see Mümin 360 on the App Store. If you are planning an app in a sensitive field, one that puts its users’ trust first, our custom software and mobile apps page explains how we work, and commissioning a mobile app walks through the process.
