In mainland Portugal and in the Autonomous Region of Madeira, clocks should be delayed by one hour when it is 2:00 am on Sunday, moving to 1:00 am. In the Autonomous Region of the Azores, the change will be made at 1:00 am, becoming 00:00 am.

The legal time will then change again on 28 March 2021, for the summer regime.

The current time change regime is regulated by a directive of Union European Law of 2020, which states that every year the clocks are moved one hour ahead and one hour back respectively on the last Sunday in March and October, marking the start and end of summer time.