Spring Forward in the case of the United States where a one-hour shift occurs at 02:00 local time, in spring the clock jumps forward from the last moment of 01:59 standard time to 03:00 DST and that day has 23 hours, whereas in autumn the clock jumps backward from the last moment of 01:59 DST to 01:00 standard time, repeating that hour, and that day has 25 hours. A digital display of local time does not read 02:00 exactly at the shift to summer time, but instead jumps from 01:59:59.9 forward to 03:00:00.0. In the European Union, on the other hand, since the shift occurs at 01:00 UTC, the autumn shift happens an hour later than the spring shift, local time.
Clock shifts are usually scheduled near a weekend midnight to lessen disruption to weekday schedules. A one-hour shift is customary, but Australia's Lord Howe Island uses a half-hour shift. Twenty-minute and two-hour shifts have been used in the past.
Coordination strategies differ when adjacent time zones shift clocks. The European Union shifts all at once, at 01:00 UTC or 02:00 CET or 03:00 EET; for example, Eastern European Time is always one hour ahead of Central European Time. Most of North America shifts at 02:00 local time, so its zones do not shift at the same time; for example, Mountain Time is temporarily (for one hour) zero hours ahead of Pacific Time, instead of one hour ahead, in the autumn and two hours, instead of one, ahead of Pacific Time in the spring. In the past, Australian districts went even further and did not always agree on start and end dates; for example, in 2008 most DST-observing areas shifted clocks forward on October 5 but Western Australia shifted on October 26. In some cases only part of a country shifts; for example, in the US, Hawaii and most of Arizona do not observe DST.