When we change our clocks
Daylight Saving Time begins for most of the United States at 2 a.m. on the first Sunday of April. Time reverts to standard time at 2 a.m. on the last Sunday of October. In the U.S., each time zone switches at a different time.
 
In the European Union, Summer Time begins and ends at 1 am Universal Time (Greenwich Mean Time). It starts the last Sunday in March, and ends the last Sunday in October. In the EU, all time zones change at the same moment.
Spring forward, Fall back
During DST, clocks are turned forward an hour, effectively moving an hour of daylight from the morning to the evening.

  United States European Union
 Year  DST Begins
at 2 a.m. 		 DST Ends
at 2 a.m. 		 Summertime
period begins
at 1 a.m. UT		 Summertime
period ends
at 1 a.m. UT
2004 April 4 October 31 March 28 October 31
2005 April 3 October 30 March 27 October 30
2006 April 2 October 29 March 26 October 29
2007 March 11 November 4 March 25 October 28
2008 March 9 November 2 March 30 October 26
2009 March 8 November 1 March 29 October 25
2010 March 14 November 7 March 28 October 31
2011 March 13 November 6 March 17 October 30

Date change in 2007
On August 8, 2005, President George W. Bush signed the Energy Policy Act of 2005. This Act changed the time change dates for Daylight Saving Time in the U.S. Beginning in 2007, DST will begin on the second Sunday of March and end the first Sunday of November. The Secretary of Energy will report the impact of this change to Congress. Congress retains the right to revert the Daylight Saving Time back to the 2005 time schedule once the Department of Energy study is complete.