⌚️🕰⏱⏰🕐Clocks in the UK go forward one hour on March 27, to officially mark the start of British Summer Time. The springing forward of clocks happens every year on the last Sunday of March in the UK. In March the clocks move forward an hour at 1am in the morning. While on the last Sunday in October they go back an hour at 2am, This year the clocks will change at 2am on Sunday October 29, 2017. March 27 2017 also marks the 10th Anniversary of Earth Hour.