London’s day hours run 83 minutes in June and 39 in December, more than twice as long
At 51.5° north London has the widest swing of the cities on these pages, so all twelve June night hours fit into 7 hours 21 minutes of darkness.
The UK keeps GMT (UTC+0) in winter and BST (UTC+1) from the last Sunday in March to the last Sunday in October. Sunrise ranges from 04:42 in mid-June to 08:06 on New Year’s Day, and sunset from 15:51 in early December to 21:21 on 20 June.
William Lilly, who practised astrology in London, printed tables of planetary hours in Christian Astrology in 1647. He had to work from tables. The calculator works the hours out for any date and any minute.
| Date | Sunrise | Sunset | Day hour | Night hour |
|---|---|---|---|---|
| 20 March | 06:05 | 18:12 | 61 min | 59 min |
| 21 June | 04:42 | 21:21 | 83 min | 37 min |
| 23 September | 06:46 | 18:58 | 61 min | 59 min |
| 21 December | 08:03 | 15:53 | 39 min | 81 min |
Times are local clock times from this calculator, with daylight saving applied where London uses it. Each planetary hour is one twelfth of the daylight or one twelfth of the night, so these two lengths set every hour of the day.
Born in London? Enter your birth date and time to see your hour
Leave the city on London, set your birth date and type your birth time into the time field. The panel names your hour and the dial turns to the planetary day you were born in. The calculator applies the British clock rules in force on your birth date, including British Double Summer Time during the Second World War. A birth before sunrise belongs to the night of the previous day, and the panel tells you when that applies.