Add clock changes in the UK to your calendar (ICS, 5KB). In the UK the clocks go forward 1 hour at 1am on the last Sunday in March, and back 1 hour at 2am on the last Sunday in October. The period when the clocks are 1 hour ahead is called British Summer Time (BST). There's more daylight in the evenings and less in the mornings (sometimes called Daylight Saving Time).