USA: Daylight Savings 2010 - when to Set Clocks, Spring & Fall; Seasons' First Days

Spring ahead March 14, 2010. Daylight Savings Time (DST) begins on the second Sunday in March at 2:00 am local time in the U.S., which in 2010 is March 14. Turn clocks ahead by one hour, ideally at bedtime on the Saturday night before. Manually adjust any timepieces and timekeeping technological devices that do not automatically adjust.

The purpose of DST-also known as Summer Time-is to extend daylight by an hour in the afternoons during spring, summer, and much of the fall. To learn about the rationale behind this concept, click here.

Fall back November 7, 2010. The return to Standard Time (ST) begins at 2:00 am local time in the U.S. on the first Sunday in November, which in 2010 is November 7. Turn clocks back by one hour, ideally at bedtime on the Saturday night before. Manually adjust any timepieces and timekeeping technological devices that do not automatically adjust.

While Indiana observes DST (since 2006), the state remains divided in telling time-80 of its 92 counties use Eastern Time while the other 12 use Central. These numbers have fluctuated during the last few years as counties have opted to switch time zones.

U.S. States that are on ST year-round are Arizona (except for Navajo Nation) and Hawaii, as are the U.S. territories (Puerto Rico, Virgin Islands, Guam, and American Samoa).

To check the time anywhere in the world, visit Google's Time Zone or Time and Date's World Clock.

The First Days of Each Season in 2010.

Spring begins March 20. The exact time is 1:32 pm Eastern Daylight Time (EDT).

Summer begins June 21. The exact time is 7:23 am EDT.

Fall begins September 22. The exact time is 11:09 pm EDT.

Winter begins December 21. The exact time is 6:38 pm Eastern Standard Time (EST)

For 2011 information, CLICK HERE.

Sources: Spring; Summer; Fall; Winter