British Summer Time (BST) starts on the last Sunday in March and ends on the last Sunday in October, at 1.00 am Greenwich Mean Time (GMT):
In spring the clocks go forward, losing an hour - at 1.00 am GMT the UK moves to 2.00 am BST
In autumn the clocks go back, giving an extra hour - at 2.00 am BST the UK moves to 1.00 am GMT
Summer time periods begin and end on the following dates:
| 2010 | 2011 | 2012 | |
| Clocks go Forward | 28th March | 27th March | 25th March |
| Clocks go Back | 31st October | 30th October | 28th October |