Hours of Darkness

No College crew is permitted to be on the water before Lighting Down or after Lighting Up. Crews on the water within 15 minutes of lighting up or lighting down must have static white lights (clearly visible) attached to both the bow and stern of the boat.

Lighting Up and Down times for 2025 are listed in the table below. All of the times are adjusted to BST where applicable. The lighting times for today and tomorrow are available on a WAP phone (http://m.cucbc.org/lighting).

Lighting down is defined as the time when the sun rises to 95° below the zenith, whilst lighting up is the time at which the sun sets to 94° below the zenith.

DayDateLighting DownLighting Up
Tuesday21/01/202507:2316:52
Wednesday22/01/202507:2216:53
Thursday23/01/202507:2116:55
Friday24/01/202507:2016:57
Saturday25/01/202507:1916:59
Sunday26/01/202507:1817:00
Monday27/01/202507:1617:02
Tuesday28/01/202507:1517:04
Wednesday29/01/202507:1417:05
Thursday30/01/202507:1217:07
Friday31/01/202507:1117:09
Saturday01/02/202507:0917:11
Sunday02/02/202507:0817:13
Monday03/02/202507:0617:14
Tuesday04/02/202507:0517:16
Wednesday05/02/202507:0317:18
Thursday06/02/202507:0117:20
Friday07/02/202507:0017:21
Saturday08/02/202506:5817:23
Sunday09/02/202506:5617:25
Monday10/02/202506:5417:27
Tuesday11/02/202506:5317:29
Wednesday12/02/202506:5117:31
Thursday13/02/202506:4917:32
Friday14/02/202506:4717:34
Saturday15/02/202506:4517:36
Sunday16/02/202506:4317:38
Monday17/02/202506:4117:40
Tuesday18/02/202506:3917:41
Wednesday19/02/202506:3717:43
Thursday20/02/202506:3517:45
Friday21/02/202506:3317:47
Saturday22/02/202506:3117:49
Sunday23/02/202506:2917:50
Monday24/02/202506:2717:52
Tuesday25/02/202506:2517:54
Wednesday26/02/202506:2317:56
Thursday27/02/202506:2117:58
Friday28/02/202506:1917:59
Saturday01/03/202506:1718:01
Sunday02/03/202506:1418:03
Monday03/03/202506:1218:05
Tuesday04/03/202506:1018:06
Wednesday05/03/202506:0818:08
Thursday06/03/202506:0618:10
Friday07/03/202506:0318:12
Saturday08/03/202506:0118:14
Sunday09/03/202505:5918:15
Monday10/03/202505:5718:17
Tuesday11/03/202505:5418:19
Wednesday12/03/202505:5218:21
Thursday13/03/202505:5018:22
Friday14/03/202505:4718:24
Saturday15/03/202505:4518:26
Sunday16/03/202505:4318:28
Monday17/03/202505:4018:29
Tuesday18/03/202505:3818:31
Wednesday19/03/202505:3618:33
Thursday20/03/202505:3318:35
Friday21/03/202505:3118:36
Saturday22/03/202505:2918:38
Sunday23/03/202505:2618:40
Monday24/03/202505:2418:42
Tuesday25/03/202505:2218:43
Wednesday26/03/202505:1918:45
Thursday27/03/202505:1718:47
Friday28/03/202505:1418:49
Saturday29/03/202505:1218:51
Sunday30/03/202506:1019:52
Monday31/03/202506:0719:54
Tuesday01/04/202506:0519:56
Wednesday02/04/202506:0319:58
Thursday03/04/202506:0019:59
Friday04/04/202505:5820:01
Saturday05/04/202505:5520:03
Sunday06/04/202505:5320:05
Monday07/04/202505:5120:07
Tuesday08/04/202505:4820:08
Wednesday09/04/202505:4620:10
Thursday10/04/202505:4420:12
Friday11/04/202505:4120:14
Saturday12/04/202505:3920:15
Sunday13/04/202505:3720:17
Monday14/04/202505:3420:19
Tuesday15/04/202505:3220:21
Wednesday16/04/202505:3020:23
Thursday17/04/202505:2720:25
Friday18/04/202505:2520:26
Saturday19/04/202505:2320:28
Sunday20/04/202505:2020:30
Monday21/04/202505:1820:32
Tuesday22/04/202505:1620:34
Wednesday23/04/202505:1420:35
Thursday24/04/202505:1220:37
Friday25/04/202505:0920:39
Saturday26/04/202505:0720:41
Sunday27/04/202505:0520:43
Monday28/04/202505:0320:45
Tuesday29/04/202505:0120:46
Wednesday30/04/202504:5920:48
Thursday01/05/202504:5720:50
Friday02/05/202504:5420:52
Saturday03/05/202504:5220:54
Sunday04/05/202504:5020:55
Monday05/05/202504:4820:57
Tuesday06/05/202504:4620:59
Wednesday07/05/202504:4421:01
Thursday08/05/202504:4221:03
Friday09/05/202504:4121:04
Saturday10/05/202504:3921:06
Sunday11/05/202504:3721:08
Monday12/05/202504:3521:10
Tuesday13/05/202504:3321:11
Wednesday14/05/202504:3121:13
Thursday15/05/202504:3021:15
Friday16/05/202504:2821:16
Saturday17/05/202504:2621:18
Sunday18/05/202504:2521:20
Monday19/05/202504:2321:21
Tuesday20/05/202504:2221:23
Wednesday21/05/202504:2021:24
Thursday22/05/202504:1921:26
Friday23/05/202504:1721:27
Saturday24/05/202504:1621:29
Sunday25/05/202504:1521:30
Monday26/05/202504:1321:32
Tuesday27/05/202504:1221:33
Wednesday28/05/202504:1121:35
Thursday29/05/202504:1021:36
Friday30/05/202504:0921:37
Saturday31/05/202504:0821:39
Sunday01/06/202504:0721:40
Monday02/06/202504:0621:41
Tuesday03/06/202504:0521:42
Wednesday04/06/202504:0421:43
Thursday05/06/202504:0321:44
Friday06/06/202504:0221:45
Saturday07/06/202504:0221:46
Sunday08/06/202504:0121:47
Monday09/06/202504:0121:48
Tuesday10/06/202504:0021:49
Wednesday11/06/202504:0021:49
Thursday12/06/202503:5921:50
Friday13/06/202503:5921:51
Saturday14/06/202503:5921:51
Sunday15/06/202503:5921:52
Monday16/06/202503:5921:52
Tuesday17/06/202503:5921:53
Wednesday18/06/202503:5921:53
Thursday19/06/202503:5921:53
Friday20/06/202503:5921:54
Saturday21/06/202503:5921:54
Sunday22/06/202503:5921:54
Monday23/06/202504:0021:54
Tuesday24/06/202504:0021:54
Wednesday25/06/202504:0121:54
Thursday26/06/202504:0121:54
Friday27/06/202504:0221:54
Saturday28/06/202504:0221:53
Sunday29/06/202504:0321:53
Monday30/06/202504:0421:53
Tuesday01/07/202504:0521:52
Wednesday02/07/202504:0521:52
Thursday03/07/202504:0621:51
Friday04/07/202504:0721:51
Saturday05/07/202504:0821:50
Sunday06/07/202504:0921:49
Monday07/07/202504:1021:48
Tuesday08/07/202504:1221:48
Wednesday09/07/202504:1321:47
Thursday10/07/202504:1421:46
Friday11/07/202504:1521:45
Saturday12/07/202504:1721:44
Sunday13/07/202504:1821:43
Monday14/07/202504:1921:41
Tuesday15/07/202504:2121:40
Wednesday16/07/202504:2221:39
Thursday17/07/202504:2421:38
Friday18/07/202504:2521:36
Saturday19/07/202504:2721:35
Sunday20/07/202504:2821:34
Monday21/07/202504:3021:32
Tuesday22/07/202504:3121:31
Wednesday23/07/202504:3321:29
Thursday24/07/202504:3521:28
Friday25/07/202504:3621:26
Saturday26/07/202504:3821:24
Sunday27/07/202504:4021:23
Monday28/07/202504:4121:21
Tuesday29/07/202504:4321:19
Wednesday30/07/202504:4521:17
Thursday31/07/202504:4721:16
Friday01/08/202504:4821:14
Saturday02/08/202504:5021:12
Sunday03/08/202504:5221:10
Monday04/08/202504:5421:08
Tuesday05/08/202504:5521:06
Wednesday06/08/202504:5721:04
Thursday07/08/202504:5921:02
Friday08/08/202505:0121:00
Saturday09/08/202505:0320:58
Sunday10/08/202505:0420:56
Monday11/08/202505:0620:54
Tuesday12/08/202505:0820:52
Wednesday13/08/202505:1020:50
Thursday14/08/202505:1220:48
Friday15/08/202505:1320:46
Saturday16/08/202505:1520:43
Sunday17/08/202505:1720:41
Monday18/08/202505:1920:39
Tuesday19/08/202505:2120:37
Wednesday20/08/202505:2220:35
Thursday21/08/202505:2420:32
Friday22/08/202505:2620:30
Saturday23/08/202505:2820:28
Sunday24/08/202505:2920:25
Monday25/08/202505:3120:23
Tuesday26/08/202505:3320:21
Wednesday27/08/202505:3520:19
Thursday28/08/202505:3620:16
Friday29/08/202505:3820:14
Saturday30/08/202505:4020:12
Sunday31/08/202505:4220:09
Monday01/09/202505:4320:07
Tuesday02/09/202505:4520:05
Wednesday03/09/202505:4720:02
Thursday04/09/202505:4920:00
Friday05/09/202505:5019:57
Saturday06/09/202505:5219:55
Sunday07/09/202505:5419:53
Monday08/09/202505:5619:50
Tuesday09/09/202505:5719:48
Wednesday10/09/202505:5919:46
Thursday11/09/202506:0119:43
Friday12/09/202506:0219:41
Saturday13/09/202506:0419:38
Sunday14/09/202506:0619:36
Monday15/09/202506:0719:34
Tuesday16/09/202506:0919:31
Wednesday17/09/202506:1119:29
Thursday18/09/202506:1219:26
Friday19/09/202506:1419:24
Saturday20/09/202506:1619:22
Sunday21/09/202506:1819:19
Monday22/09/202506:1919:17
Tuesday23/09/202506:2119:15
Wednesday24/09/202506:2319:12
Thursday25/09/202506:2419:10
Friday26/09/202506:2619:08
Saturday27/09/202506:2819:05
Sunday28/09/202506:2919:03
Monday29/09/202506:3119:01
Tuesday30/09/202506:3318:58
Wednesday01/10/202506:3418:56
Thursday02/10/202506:3618:54
Friday03/10/202506:3818:51
Saturday04/10/202506:3918:49
Sunday05/10/202506:4118:47
Monday06/10/202506:4318:44
Tuesday07/10/202506:4418:42
Wednesday08/10/202506:4618:40
Thursday09/10/202506:4818:38
Friday10/10/202506:4918:36
Saturday11/10/202506:5118:33
Sunday12/10/202506:5318:31
Monday13/10/202506:5518:29
Tuesday14/10/202506:5618:27
Wednesday15/10/202506:5818:25
Thursday16/10/202507:0018:23
Friday17/10/202507:0118:20
Saturday18/10/202507:0318:18
Sunday19/10/202507:0518:16
Monday20/10/202507:0618:14
Tuesday21/10/202507:0818:12
Wednesday22/10/202507:1018:10
Thursday23/10/202507:1218:08
Friday24/10/202507:1318:06
Saturday25/10/202507:1518:04
Sunday26/10/202506:1717:02
Monday27/10/202506:1817:00
Tuesday28/10/202506:2016:59
Wednesday29/10/202506:2216:57
Thursday30/10/202506:2416:55
Friday31/10/202506:2516:53
Saturday01/11/202506:2716:51
Sunday02/11/202506:2916:50
Monday03/11/202506:3016:48
Tuesday04/11/202506:3216:46
Wednesday05/11/202506:3416:45
Thursday06/11/202506:3616:43
Friday07/11/202506:3716:41
Saturday08/11/202506:3916:40
Sunday09/11/202506:4116:38
Monday10/11/202506:4216:37
Tuesday11/11/202506:4416:35
Wednesday12/11/202506:4616:34
Thursday13/11/202506:4716:33
Friday14/11/202506:4916:31
Saturday15/11/202506:5116:30
Sunday16/11/202506:5216:29
Monday17/11/202506:5416:27
Tuesday18/11/202506:5516:26
Wednesday19/11/202506:5716:25
Thursday20/11/202506:5916:24
Friday21/11/202507:0016:23
Saturday22/11/202507:0216:22
Sunday23/11/202507:0316:21
Monday24/11/202507:0516:20
Tuesday25/11/202507:0616:19
Wednesday26/11/202507:0816:18
Thursday27/11/202507:0916:18
Friday28/11/202507:1016:17
Saturday29/11/202507:1216:16
Sunday30/11/202507:1316:16
Monday01/12/202507:1516:15
Tuesday02/12/202507:1616:15
Wednesday03/12/202507:1716:14
Thursday04/12/202507:1816:14
Friday05/12/202507:1916:13
Saturday06/12/202507:2116:13
Sunday07/12/202507:2216:13
Monday08/12/202507:2316:13
Tuesday09/12/202507:2416:12
Wednesday10/12/202507:2516:12
Thursday11/12/202507:2616:12
Friday12/12/202507:2716:12
Saturday13/12/202507:2816:12
Sunday14/12/202507:2916:12
Monday15/12/202507:2916:13
Tuesday16/12/202507:3016:13
Wednesday17/12/202507:3116:13
Thursday18/12/202507:3116:14
Friday19/12/202507:3216:14
Saturday20/12/202507:3316:14
Sunday21/12/202507:3316:15
Monday22/12/202507:3416:15
Tuesday23/12/202507:3416:16
Wednesday24/12/202507:3416:17
Thursday25/12/202507:3516:17
Friday26/12/202507:3516:18
Saturday27/12/202507:3516:19
Sunday28/12/202507:3516:20
Monday29/12/202507:3516:21
Tuesday30/12/202507:3516:22
Wednesday31/12/202507:3516:23

XML and CSV files of the hours of darkness for the current year are available. Other webmasters may wish to use these to display the lighting up and down times on their own websites.

» XML Data for 2025
» CSV Data for 2025

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