Updated 3 November 2026.
Each prayer time is the moment the sun reaches a set position: Fajr and Isha when it is a set angle below the horizon, Dhuhr after its highest point, Asr when shadows reach a set length, and Maghrib at sunset. Timetables differ because they pick different angles, shadow rules and short-night rules, not because they see a different sun.
Your mosque’s timetable comes first. This page explains arithmetic, not rulings. No scholar or imam has reviewed this site.
By UmmahSky. Every time on this page was worked out by the code this site runs (adhan-js 4.4.6, 2027 dates). How we test.
The five times and the sun
| Prayer | Where the sun is | What timetables choose |
|---|---|---|
| Fajr | A set angle below the horizon, before sunrise | The angle (12° to 19.5° here), and a rule for short summer nights |
| Sunrise | The top of the sun at the horizon | Little: some allow for height above sea level |
| Dhuhr | Just after its highest point of the day | Minutes added after noon (UK seasonal minutes add 5) |
| Asr | When a shadow reaches a set length | The Shafi or the Hanafi shadow rule |
| Maghrib | The top of the sun at the horizon, after sunset | Minutes added after sunset (UK seasonal minutes add 3) |
| Isha | A set angle below the horizon, after sunset, or a fixed time after Maghrib | The angle or the fixed minutes, and a short-night rule |
Fajr and Isha: sun angles
The deeper the angle, the earlier Fajr and the later Isha. In London in March each degree moves Fajr by about 7 minutes: 15° and 18° are 21 minutes apart.
| Angle | Fajr | Isha |
|---|---|---|
| 12° | 04:49 | 19:28 |
| 15° | 04:29 | 19:48 |
| 18° (Isha 17°) | 04:08 | 20:02 |
| 19.5° (Isha 17.5°) | 03:57 | 20:06 |
| Angle | Fajr | Isha |
|---|---|---|
| 12° | 06:40 | 17:17 |
| 15° | 06:19 | 17:37 |
| 18° (Isha 17°) | 05:59 | 17:51 |
| 19.5° (Isha 17.5°) | 05:49 | 17:54 |
| Angle | Fajr | Isha |
|---|---|---|
| 12° | 06:01 | 17:53 |
| 15° | 05:46 | 18:08 |
| 18° (Isha 17°) | 05:30 | 18:18 |
| 19.5° (Isha 17.5°) | 05:23 | 18:21 |
Some timetables don’t use an angle for Isha at all. Umm al-Qura’s calendar sets Isha 90 minutes after sunset (120 in Ramadan), and both Sydney timetables we compared sit within a minute of that pattern on average.
Asr: two shadow rules
Asr starts when an upright stick’s shadow is its noon shadow plus one stick length (the Shafi, Maliki and Hanbali reading) or plus two (the Hanafi reading). The Hanafi time is always later.
| Date | Dhuhr | Shafi Asr | Hanafi Asr | Gap |
|---|---|---|---|---|
| 21 March 2027 | 12:13 | 15:27 | 16:17 | 50 min |
| 21 June 2027 | 13:07 | 17:25 | 18:40 | 75 min |
| 21 December 2027 | 12:03 | 13:37 | 14:07 | 30 min |
| Date | Dhuhr | Shafi Asr | Hanafi Asr | Gap |
|---|---|---|---|---|
| 21 March 2027 | 13:03 | 16:29 | 17:22 | 53 min |
| 21 June 2027 | 11:57 | 14:36 | 15:16 | 40 min |
| 21 December 2027 | 12:53 | 16:38 | 17:54 | 76 min |
Through 2027 the gap is 29 to 75 minutes in London (51 on average) and 40 to 76 in Sydney. It is widest in summer, when the sun is high and shadows grow slowly. That’s why Asr is the largest single difference for anyone whose mosque uses the other rule: about 52 minutes on average across the UK timetables we compared.
Short summer nights
In London the sun doesn’t go 18° below the horizon from 23 May to 21 July (60 nights in 2027), so an 18° Fajr never happens and a rule has to set it.
| Rule | Fajr | Isha |
|---|---|---|
| Middle of the night | 01:02 | 01:02 |
| One seventh of the night | 03:40 | 22:25 |
| Twilight angle | 02:31 | 23:27 |
| Seasonal minutes (UK starting setting) | 02:43 | 22:42 |
- Middle of the night: Fajr and Isha no further than halfway between sunset and sunrise. On this date they meet.
- One seventh of the night: no further than a seventh of the night from sunrise and sunset.
- Twilight angle: a share of the night in proportion to the angle.
- Seasonal minutes: minutes from sunrise and sunset that change through the year; 18° is used only when it is nearer. This is our UK starting setting.
The seasonal formula changes at 55° north. Two places a few kilometres apart, either side of the line, got Fajr 02:24 and 03:30 on 22 June 2027. So from 55° we offer no starting setting: in Glasgow on 21 June our settings range from 01:19 to 03:36. More on short nights.
Why mosque timetables differ
When we compared 1,350 prayer times at 25 cities on 3 dates with two other prayer-time websites and one calculation service, every gap over 2 minutes came from one of these causes. None was left unexplained.
| Cause | Typical size | Measured example |
|---|---|---|
| Fajr angle or short-night rule | Up to 2 hours in a UK summer | Wifaqul Ulama’s London PDF and Harrow Central Mosque are 42.5 and 0.1 minutes from our seasonal Fajr on average |
| Asr rule | 24 to 80 minutes in our cities | London, 21 June 2027: Shafi 17:25, Hanafi 18:40 |
| Fixed Isha | Up to 37 minutes in our Australian cities on 21 June and 21 December | Sydney timetables use 90 minutes after sunset: 0.3 min from that setting, 7.9 from 17° |
| Minutes added after noon and sunset | 0 to 5 minutes in our settings | UK seasonal minutes add 5 to Dhuhr and 3 to Maghrib |
| Height above sea level | About 0.5 to 4.3 minutes at sunrise and sunset in our cities (our estimate) | Canberra, 571 m: one site allows for height, we don’t |
| Rounding and the city point | Under a minute | 0.1° of longitude moves every time by about 24 seconds |
How we check the sun
The astronomy is the part everyone agrees on, and we checked it: sunrise, noon and sunset from our code were within 2.7 seconds of NASA JPL’s Horizons at 18 cities for every day of 2027.
So when two timetables differ by minutes, the cause is a choice from the list above. To see which choice your mosque makes, use Match my mosque, or compare methods for your city.