It is obligatory up on all Muslims (males and females) above the age of maturity (البلوغ) to offer the five daily prayers (الصلاة). Each prayer lasts about 10 - 15 minutes (except Friday Jummah prayer taking 30 - 40 minutes longer) and comprises of a set of body movements including standing, bowing, sitting and prostration.

It is also obligatory to offer the daily prayers at the stated times, as ordered in the Quran:

إِنَّ الصَّلَاةَ كَانَتْ عَلَى الْمُؤْمِنِينَ كِتَابًا مَّوْقُوتًا
“Verily, the prayer is enjoined on the believers at fixed hours.” [Quran 4:103]

The start/end of the prayers are derived from hadith and related to the position of the sun, as stated below:

Name Description
1. Fajr (الفجر) /Dawn When the first rays of light appear on the horizon (Subh Sadiq) and lasts until sunrise. Historical data shows the first rays of light starts to appear when the sun is 18° below the horizon but some argue it should be 15°. So, the cautious approach is to close your fast at 18° and pray Fajr at 15°.
2. Dhuhr (الظهر) /Midday When the sun passes the Meridian (Zenith) and lasts until Asr
3. Asr (العصر) /Afternoon When the shadow of an object is equal to its length (or twice its length for Hanafi Madhab) until sunset
4. Maghrib (المغرب) /Sunset When the upper limb of the sun disappears below the horizon at sunset
5. Isha (العشاء) /Night When the last rays of light disappear from horizon and total darkness takes place. This happens at the disappearance of white twilight (18°), but some follow the disappearance of red twilight (15°); until Fajr, but makruh (disliked) to unnecessarily delay after middle of night.

The diagram below shows the five prayers times based on the sun position during 24 hrs of the day.

prayer-times diagram3

Persistent Twilight

Prayer times can be calculated for all locations near the equator with real data based on the position of the sun throughout the year, which do not suffer from the persistent twilight related problem associated with high latitude countries, such as the UK. The annual prayer times graph for Makkah below shows all the timings throughout the year are very similar with small differences between the night lengths (sunset to sunrise) of the summer and winter seasons.

prayer-times-graph-makkah
Codes: Fajr (F), Sunrise (SR), Dhuhr (Z), Asr 1 (A1), Asr 2 (A2), Sunset (SS), Isha (I), Isha/7 (I7)

However, for locations above 48° latitude, such as the UK has a period of time during the summer months (May - July) where the sun never goes down low enough after sunset to establish true darkness, hence the evening twilight persists throughout the night. This abnormal situation results in not having the true Fajr or Isha times as shown in the annual prayer times graph for York (UK) below. The Fajr (F) and Isha (I) curves simply disappear!

prayer-times-graph-york

Therefore, the Fuqaha (Muslim Jurists) have suggested a number of methods to estimate the prayer times based on the famous Dajjal hadith, (narrated by Al-Nawwas ibn Sam`an), in which the Messenger of Allah (ﷺ) was asked:

“And how long would he stay on the earth? He (ﷺ) said: For forty days, one day like a year and one day like a month and one day like a week and the rest of the days would be like your days. We said: Allah's Messenger, would one day's prayer suffice for the prayers of day equal to one year? Thereupon he (ﷺ) said: No, but you must make an estimate of time (and then observe prayer).” [Muslim]

The estimation rules for persistent twilight periods are given below.

Name Description
1. Nearest Latitude (أقرب آل بلد ) Add the interval between sunset and Isha for a location on latitude 48° to the local sunset time to obtain time for local Isha. Similarly the interval between Fajr and sunrise for a location on latitude 48° is subtracted from local sunrise to obtain local Fajr time.
2. Nearest Day (أقرب الأيام ) Use Fajr and Isha times from the last day when it was possible to calculate these times in the normal way for that location.
3. Middle of Night (نصف الليل ) Split interval between sunrise and sunset into two halves. Isha is offered before the midpoint (e.g. 15 minutes before) and Fajr is offered after the midpoint
4. One Seventh of Night (واحد السابع ليلة ) Split interval between sunset and sunrise into seven segments. Isha is offered after the first segment and Fajr is offered after the sixth segment (but see Notes below).
Notes for Ramadan

Although the five daily prayer times have been established from Hadith, the start of fasting in Ramadan has been specifically mentioned in the Quran, where Allah says:

وَكُلُوا وَاشْرَ‌بُوا حَتَّىٰ يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ‌
“And eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night)” Quran (2:187)

Therefore, many Muslim scholars in the UK prefer to use the Nearest Day (Aqrab Al-Ayyam) rule for end of Suhoor (سحور‎) in Ramadan, but use the One-Seventh night (Sube Al-Lail) rule for Isha/Tarawih prayer from the Dajjal Hadith. The annual prayer times graph for York shows the extra 1/7th time curve for Isha (I7) and the solid blue line shows the last true (Nearest Day) time for Fajr (F) during persistent twilight.

Timetable Errors

From the annual prayer times graph for locations near the equator, such as for Makkah with almost equal night length, it can be seen there is almost a constant time difference between Fajr to Sunrise and Sunset to Isha throughout the year. Therefore, any Fajr/Isha prayer times produces for such locations with a fixed offset from sunrise/sunset (e.g. 1:20 hrs or 1:40 hrs) will not be far out from the true times based on a solar depression angle (e.g. -18°). However, for high latitude locations like the UK, applying a fixed offset from sunrise/sunset to derive Fajr/Isha is a gross misjudgement, which is likely to make the prayers/fasting of Ramadan null and void.

So, please verify all timetables from Muslim astronomers, who are familiar with validating observation results (e.g. by dark-adapting the eyes and observing away from light pollution areas). Your questions may include: is the height (altitude) of the location included in the calculation or is it fixed at sea-level as is the case with navigation/agricultural use; is the refraction/parallax adjustment (caused by heavy medium of the earth) added to the calculation; are the sunrise/sunset times based on the centre of the sun or upper limb of the sun against the horizon, etc.

References:
1. Prayer Times for UK & Ireland by Maulana Yakub Qasmi and Dr Tariq Muneer (1989)
2. Prayer Times Calculator v3.0 by Dr Monzur Ahmed (2010)

Checked by: Mufti Amjad Mohammed

Related: How to make Hijri Calendar Prayer Timetables