Switches at 00:00: Regions that alternate between EGT and EGST, including Ittoqqortoormiit.
Daylight saving time starts, but the time zone changes from EGT to CGST (both UTC -1), so the time zone offset stays the same.
Clocks should skip one hour forward when daylight saving time starts.
Clocks will not skip an hour in Eastern Greenland, because the time zone will change when daylight saving time starts.
Summer time starts at the same time in all of Europe (except Moldova), but at different local times, depending on the time zone.
Contrary to other locations that observe daylight saving time, Ireland has daylight saving time in the winter, and standard time in the summer. Winter time is still one hour behind summer time.
Türkiye and Iceland do not change between standard time and daylight saving time.