Posts Tagged ‘2017’

UK Ramadan fasting times for 2017

May 22, 2017

Bismillah. As I’ve written about before, there are different views on excessive fasting hours in the summer at high latitudes such as the UK. I am not going to repeat those, but try to provide the scientific, astronomical data, information and knowledge to help support others to come to their own conclusions.

In this post, I give the dawn, sunset & possible fasting times for 2017, when mid-summer occurs towards the end of Ramadan: the average fasting times are slightly shorter than last year (2016), when they were maximum in the 33-year lunar/solar cycle, but not by much.

*I urge mosque timekeepers (muwaqqits) or others who develop fasting timetables to be transparent about the method they are using, and not vague references like “fiqh according to Madhhab X” because there are many views in every Madhhab. E.g. using an 18-degree or even 15-degree rule gives no timings for most of the UK. Fasting timetables in the UK summer should clearly state what method is used to arrive at the beginning time of fasting. Many timetables have excessive gaps between ‘dawn’ and sunrise of 2-3 hours with no sensible justification, since this is merely one possibility amongst many others and is indeed the most difficult for people. Indeed, with the summer midnight being at 1am BST, some of these timetables are forcing people to fast from soon after midnight. With the sunset-sunrise night length being 6-8 hours across the UK, the most reasonable view within this paradigm in my view is that of the last 1/6th, 1/7th or 1/8th of the night, giving a fasting time beginning an hour before dawn. However, other approaches are even more preferable. Over to others for discussion and to arrive at their own conclusions.*

Examples of dawn/sunset timings for the UK, 2017 (four UK capital cities)

This data is taken from HMNAO’s Websurf 2.0 website, and was reproduced with permission by the ASCL in their Ramadan 2017 guidelines. I have used the four UK capital cities, with three dates for each, roughly corresponding to the beginning, middle & end of Ramadan.

Date City Dawn (AST) Dawn (15D) Dawn (NAUT) Sunrise Sunset Fasting length (AST) Fasting length (15D) Fasting length (NAUT)
27 May London *** 0220 0305 0454 2103 *** 18:43 17:58
10 June   *** 0139 0245 0444 2117 *** 19:38 18:32
25 June   *** 0122 0243 0444 2122 *** 20:00 18:39
27 May Ed’burgh *** *** 0201 0441 2140 *** *** 19:39
10 June   *** *** *** 0428 2157 *** *** ***
25 June   *** *** *** 0428 2203 *** *** ***
27 May Cardiff *** 0232 0318 0506 2115 *** 18:43 17:57
10 June   *** 0152 0257 0456 2129 *** 19:36 18:32
25 June   *** 0136 0255 0457 2134 *** 19:58 18:39
27 May Belfast *** *** 0245 0500 2143 *** *** 18:58
10 June   *** *** 0159 0448 2158 *** *** 19:59
25 June   *** *** 0134 0448 2204 *** *** 20:30

refers to astronomical twilight, when begins or ends when the sun is 18 degrees below the horizonKey:

15D refers to when the sun is 15 degrees below the horizon

NAUT refers to nautical twilight, when begins or ends when the sun is 12 degrees below the horizon

The astronomical definition of “dawn” is disputed, with various Muslim religious authorities adopting one of the three possible definitions given above.

*** in the above table means that the timing is not available, because the sun does not reach that far below the horizon. This happens every year during the summer at high latitudes, such as the UK.



  1. As confirmed by HMNAO, there is always a possible error of 1-2 minutes in sunrise and sunset timings: although we can calculate exactly the position of the sun relative to our horizons, refraction of the sun’s rays can introduce an error: the sun may be below the horizon but we see it just above, due to refraction.  (This does not always happen, of course: hence the error will be zero, one or two minutes.) This means that technically, mosque prayer timetables may wish to add 2 minutes to sunset timings and subtract 2 minutes from sunrise timings, just to be safe about the timings of the sunset and dawn prayers, and for breaking the fast.  However, this might also be hair-splitting: I recommend making these adjustments, but would not worry if they are not made.
  2. If we use astronomical twilight (Sun’s depression = 18 degrees) as the start of dawn, this does not occur at all during Ramadan 2017 in any of the four capital cities. Therefore, the fasting start time and fasting length would be undefined.
  3. If we use (Sun’s depression = 15 degrees) as the start of dawn, this does not occur at all during Ramadan 2017 in Edinburgh or Belfast. Therefore, the fasting start time and fasting length would be undefined in those cities. However, it does occur in London and Cardiff, giving fasting lengths of 19.5-20 hours during the month.
  4. If we use nautical twilight (Sun’s depression = 12 degrees) as the start of dawn, this results in fasting hours during Ramadan 2017 in London and Cardiff of 18-19 hours, and in Belfast of 19-20.5 hours. We only get defined fasting hours at the beginning of Ramadan for Edinburgh, of 19.5-20 hours.
  5. Hence, it should be obvious that some ijtihad is required, eg a fraction of the night or a lower angle of the Sun below the horizon to designate the “beginning” of dawn. Another option is sunrise-sunset fasting rather than dawn-sunset, as done by some of the Sahaba (Tafsir Ibn Kathir & Ibn Hazm’s Al-Muhalla), or other, non-literalist options that I have described elsewhere.

NB: Our local latitude determines the lowest angle the Sun will dip below the horizon at mid-summer (~22 June). This angle can easily be calculated by subtracting 66.5 degrees (the latitude of the Arctic & Antarctic Circles) from the local latitude.


Within the Arctic Circle (66.5 deg or higher latitude), lowest Sun angle = zero or higher: the sun doesn’t set at all in the “land of the midnight sun.”

Edinburgh (56.0 deg lat): lowest Sun angle at midsummer = 56.0 – 66.5 = 10.5 deg below the horizon

Belfast (54.6 deg lat): lowest Sun angle at midsummer = 54.6 – 66.5 = 11.9 deg below the horizon

London & Cardiff (both 51.5 deg lat): lowest Sun angle at midsummer = 51.5 – 66.5 = 15 deg below the horizon

*NB: even using these angles of 10.5 deg, ~12 deg, 15 deg & 15 deg for Edinburgh, Belfast, London & Cardiff respectively will give very long fasting hours, as the table of timings above demonstrates.

Btw for Paris (48.9 deg lat): lowest Sun angle at midsummer = 48.9 – 66.5 = 17.6 deg below the horizon, so using the 18-degree rule gives no timings for Paris or anywhere north of it either at midsummer.

Have a blessed Ramadan 1438 / 2017!

Usama Hasan, Fellow of the Royal Astronomical Society, UK