Ireland uses Irish Standard Time (IST, UTC+01:00; Irish: Am Caighdeánach Éireannach) in the summer months and Greenwich Mean Time (UTC+00:00; Meán-Am Greenwich) in the winter period. (Roughly half of the state is in the 7.5°W to 22.5°W sector, half is in the same sector as Greenwich: 7.5°E to 7.5°W). The instant of transition to and from daylight saving time is synchronised across Europe. In Ireland, winter time begins at 02:00 IST on the last Sunday in October (changing the clocks to 01:00 GMT), and ends at 01:00 GMT on the last Sunday in March (changing to 02:00 IST).