Clocks go forward overnight

Daylight saving time starts when clocks go forward by one hour at 1am tomorrow

Dr David Malone from Maynooth University Departments of Mathematics and Statistics explains why the clocks change for daylight saving time. Video: Maynooth University

Daylight saving time starts tomorrow when clocks go forward by one hour.

Summer time will commence at 1am Greenwich Mean Time and clocks and watches should be put forward one hour at that time.

The change will mean the loss of one hour of sleep for many but means that evenings will have more daylight and mornings will have less.

Summer time will end at 1am Greenwich Mean Time on Sunday 25th October 2015.