Winter time is to officially begin tonight, with clocks going back by one hour.
At 2am tonight clocks will go back by one hour to 1am, although most smartphones will automatically update.
The clock change brings Ireland from Daylight Saving Time to Greenwich Mean Time.
For most people, this will mean an extra hour in bed. But it's bad news for parents who will be woken up by small children at 6am instead of 7am.
