The information presented here has been calculated for the vicinity of the Olympic Stadium at Stratford in East London at 00° 01' West and 51° 32' North. All the timings are given in British Summer Time (BST). Information on the first sighting of the new crescent Moon from the venue is provided as well as twilight and sunrise/set times which may form the basis of early morning and late evening prayer times. During Ramadan, all the twilight times occur for London. This is not true for more northerly locations where astronomical twilight will not occur for anything up to another month.
New Moon occurs on Thursday July 19th at 05:24 BST. However, the new crescent moon will not sighted in the area around the Olympic village on the Thursday or the Friday as the Moon sets just before the Sun on July 19th and just after the Sun on July 20th. A sighting may be possible after sunset on Saturday July 21st at approximately 21:20 BST but the twilight sky will still be very bright and the Moon will be only 2° above the horizon. A more likely sighting is possible at about 21:20 BST on Sunday July 22nd halfway into civil twilight with the Moon just over 5° above the western horizon.
For Mecca, in Saudi Arabia, it is extremely unlikely that the 11.7-hour old crescent moon will be sighted on July 19th as it sets a few minutes after the Sun. However, the crescent moon may well be sighted on July 20th low down in the western sky at the end of civil twilight. A sighting the following day would be even more likely.
|Visibility of the New Crescent Moon|
|July 19th||Extremely unlikely||Extremely unlikely|
|July 20th||Possible||Extremely unlikely|
|July 22nd||Very likely||More likely|
The above visibility information assumes that sightings are being made under clear weather conditions with little or no haze. Further information about sighting the new crescent moon can be found on our Crescent Moon Watch site and timings for other locations can calculated using the Moon_Viz option on our Websurf site.
In the period from the possible start of Ramadan to the end of the Olympic Games, the times (in BST) of sunrise and sunset and the start and end of the twilights when the Sun is 18° (astronomical twilight), 15° and 12° (nautical twilight) below the horizon are as follows:-
|Date||Twilight Starts||Sun||Twilight Ends|
You will notice that two times are given for the end of the −18° (astronomical) twilight on July 27th. On that day astronomical twilight ends at 00:05 BST, starts at 02:09 BST and ends at again at 23:59 BST. On July 28th, astronomical twilight starts at 02:14 BST and ends at 23:54 BST. This pair of phenomena is a natural consequence of the end of an increasing period of astronomical twilight passing over a midnight.
Further information about twilight times and prayer times for other locations can be calculated using the Rise_Set and Prayers options respectively on our Websurf site.