Since 1966, most of the United States has observed Daylight Saving Time from at 2:00 a.m. on the first Sunday of April to 2:00 a.m. on the last Sunday of October. Beginning in 2007, most of the U.S. will begin Daylight Saving Time at 2:00 a.m. on the second Sunday in March and revert to standard time on the first Sunday in November. In the U.S., each time zone switches at a different time.
In the European Union, Summer Time begins and ends at 1:00 a.m. Universal Time (Greenwich Mean Time). It begins the last Sunday in March and ends the last Sunday in October. In the EU, all time zones change at the same moment.