Prayer times and Calendar explained

One of the most popular features on our website is the daily prayer times with Islamic date, which is why it’s almost on every page.

We’re often asked where these come from, and why there are sometimes differences between mosques, so here we try to explain.

Islamic calendar

The Islamic calendar has 12 lunar months, each month beginning with the sighting of the new Moon. Each month is either 29 or 30 days long, so there are 354 or 355 days in the lunar year – shorter than solar year, which is why Islamic dates appear earlier each year compared to the Western calendar.

Websites or apps that give the date and time of the new Moon can’t be relied on for determining the Islamic date, because these are not based on the sighting of the new Moon. Sighting depends on many factors, such as how many hours old the new Moon is, where it is in the sky after sunset, and of course the weather.

So, Islamic dates are known only approximately in advance; any calendar may be off by a day, depending on when the new Moon is actually sighted. There are several methods for producing Islamic calendars; we currently use the Umm al-Qura Islamic calendar, and adjust it (once a month) if the new Moon is sighted on a different day.


We pray Jum’ah, Taraweeh, Fajr and Isha in congregation. During summer months we also pray Maghrib in congregation.

How the prayer times are calculated

Our prayer times are sourced from for Cambourne (52.2178° N, 0.0662° W). Please, also see  How We Calculate on

Cambridge Central Mosque also uses the same source for Cambridge.


This is between daybreak and sunrise. During Ramadan, the jamā‘ah (congregational prayer) time for Fajr is 10-20 minutes after Fajr start time.


Dhuhr is after the Sun passes its highest point.

Jum’ah – On Fridays, instead of the Dhuhr there is the special Jum’ah (Friday) congregational prayer.

  • Summer – Jum’ah first Adhan is at 1:10 pm, Jumu’ah Khutbah at 1:20 pm and jamā‘ah at about 1:35 during BST
  • Winter – Jum’ah first Adhan is at 1:00 pm, Jumu’ah Khutbah at 1:05 and jamā‘ah at about 1:30 during GMT


‘Asr is calculated with either one shadow length (non-Hanafi), or two shadow lengths (Hanafi) – known as Mithl 1 and Mithl 2 respectively. Our calendar uses Mithl 2, which is same as Cambridge Central Mosque.


There is a difference in ‘theoretically calculated sunset’ and ‘actual sunset’. Maghrib time is actual sunset.

For Maghrib or Islamic sunset, at least 3 minutes must be added to the ‘theoretically calculated’ time of astronomical sunset. For details see FAQ at

We pray Maghrib in congregation during summer months (BST). The time is few minutes after Maghrib start time, depending on the feasibility of booking the venue.


This begins after dusk. The jamā‘ah time in Cambourne depends on feasibility of booking the venue.


Where are these prayer times valid?

If you are within Cambourne or surrounding villages, then you can use these times.

I live outside the area of your timetable, what should I do?

You should follow your nearest mosque.