Clocks in Northern Ireland advance one hour at 1:00 a.m. on Sunday. The change occurs on the weekend to reduce disruption to schools and businesses.

Daylight saving time provides an extra hour of evening daylight in spring. The practice began in the UK in 1916 to extend use of summer daylight.

Devices connected to the internet, such as smartphones and computers, update automatically. Some watches and clocks require manual adjustment.

Supporters cite benefits including lower energy use, extended evenings for leisure and tourism, more outdoor exercise, and fewer road accidents.

Opponents point to risks from darker mornings and disruptions to livestock routines for farmers.

The UK maintains the clock changes with no plans to end them.