What the London calculator works out, and why it isn't the London Unified timetable
The times on this page are calculated for one point in central London. They aren't copied from a mosque timetable. The starting profile is Muslim World League (MWL). Under this profile, Fajr is based on the sun being 18° below the horizon before dawn, and Isha on the sun being 17° below the horizon after sunset. In a London summer, the twilight rule can limit or replace these two times. The other prayers also come from the sun's position:
- Dhuhr follows solar noon. The MWL profile adds one built-in minute.
- Asr uses the Standard rule. It begins when an object's shadow equals its height plus its noon shadow.
- Maghrib is at sunset.
Many people in London know their prayer times from a London Unified timetable. The East London Mosque's explanation of its timetable describes these as start times that several mosques share. Their Fajr and Isha are based on work by Hizbul Ulama. MWL's 18° and 17° are a general convention, not that timetable, so the calculator never labels its results as London Unified. If you compare the two, look at Fajr and Isha first, because these two times depend on the twilight convention.
To use a different convention, change these settings:
- Calculation profile changes the method for Fajr and Isha. The calculation methods guide describes each profile.
- Asr calculation switches between Standard and Hanafi. Under Hanafi, Asr begins when the shadow reaches twice the object's height plus its noon shadow.
- Twilight rule sets a limit on Fajr and Isha. It applies when the twilight angle gives no time, and also when the angle's time falls outside the share of the night that the rule allows. This matters in a London summer, as the next section explains.
Two sources can differ by a few minutes even when their methods look similar. Rounding, added minutes and different reference points can all cause this. The guide to why prayer times differ explains these causes.
GMT, BST and London's short summer nights
London uses the IANA timezone Europe/London. According to GOV.UK's clock-change dates, the clocks went forward to BST (UTC+1) on 29 March 2026 and back to GMT (UTC+0) on 25 October 2026. In 2027 they go forward on 28 March and back on 31 October. The calculator uses whichever clock applied on the date you choose, so you never need to add or remove an hour yourself.
The two dated examples below use the same settings: the central London point, MWL 18°/17°, Standard Asr, the angle-based twilight rule and no manual minutes. Only the date changes.
- , on GMT: the sun sinks far enough below the horizon for both angles to apply. Fajr at 05:59 and Isha at 18:15 come directly from the 18° and 17° angles.
- , on BST: around the June solstice, the sun at London never gets as far as 17° below the horizon, so neither angle is reached. Instead, the angle-based rule limits Fajr and Isha to a share of the night. The night runs from Maghrib at 21:22 to Sunrise at about 04:43, which is roughly 7 hours 21 minutes. The rule places Fajr 18/60 of that night before Sunrise, at 02:31. It places Isha 17/60 of the night after Maghrib, at 23:27. Both times carry the label Twilight rule limit.
Dhuhr shows how the clock and the sun combine. It is 12:11 on 15 January and 13:03 on 21 June. BST moves the clock forward an hour, while solar noon itself comes several minutes earlier in June than in mid-January.
Choosing a summer convention
The angle-based rule is only the starting choice. In the weeks around the June solstice, twilight in London can last all night, and conventions differ on how to set Fajr and Isha.
If you follow a different approach, change Twilight rule or Calculation profile, then check the label on each time. Some settings put Isha after midnight. In that case, Isha shows a next-day badge, but it is still the Isha for the evening of the calculation date. The high-latitude guide explains each rule.
| Example settings | Calculation date | Fajr | Maghrib | Isha | Load this example |
|---|---|---|---|---|---|
| Winter, GMT | 15 Jan 2026 | Load this example | |||
| Midsummer, BST | 21 Jun 2026 | Twilight rule limit | Twilight rule limit | Load this example |
Scroll sideways to see all columns.
London mosque timetables, jamaah times and Jumu'ah
A calculated start time is when a prayer's time begins. A mosque's jamaah time is when it holds the congregation prayer, and each mosque sets this itself. Each mosque also sets its own Jumu'ah time on Fridays. The calculator gives Dhuhr for a Friday like any other day, but it doesn't list Jumu'ah times. Check these with your mosque.
The East London Mosque prayer times page is one example of a published London timetable. The mosque's explanation separates the London Unified start times from its own jamaah times. It also shows two Asr start columns, Mithl 1 and Mithl 2. Mithl 1 uses the same shadow rule as the calculator's Standard Asr, and Mithl 2 uses the same rule as Hanafi. Matching the Asr rule doesn't make the calculator's other times London Unified.
To compare the calculator with a mosque you attend:
- Check the mosque's timetable or explanation to see which start times it uses and whether its Asr is Mithl 1 or Mithl 2.
- Set Asr calculation to match. If the mosque names a calculated method that the calculator offers, also set Calculation profile and Twilight rule.
- Compare several dates, including one in winter and one near midsummer.
- If the mosque follows a maintained timetable such as London Unified, use its published times for both start times and jamaah.
A few matching times on one date don't show which method a mosque uses. Fajr and Isha in particular can match on one day and drift apart a few weeks later.
Month tables across the clock change, other London locations and the Qibla
Monthly timetable lists every day of a month for the current point and settings. Choose your profile, Asr rule and twilight rule before you build the month, then press Print to keep a paper copy.
Two months show a one-hour step:
- March 2027: from 28 March, when BST starts, the times move about an hour later on the clock.
- October 2027: from 31 October, when GMT returns, the times move about an hour earlier.
This step comes from the clock change, not from an error. In other months, the times shift a little from day to day.
Using a point other than central London
The starting point, 51.5074, −0.1278, is an approximate city centre. Greater London covers a wide area. Solar times shift by about four minutes for each degree of longitude, so a home or mosque in outer London may get slightly different times. In summer, latitude also affects Fajr and Isha.
To calculate times for your own point:
- Use my location asks your browser for your position, but only when you press it. The privacy page explains how this works.
- Enter coordinates instead lets you type a latitude and longitude, for example from a map.
Then check that Timezone for this location shows Europe/London and press Calculate times. Reset restores the central London point and the MWL starting settings.
Qibla from London
To find the prayer direction, open the Qibla direction from London, UK. You can also press Find Qibla in the calculator. If you do, check that the Qibla tool shows the same point.