Daylight Saving Time (Also Known as Daylight Savings Time)

On Sunday March 13 at 2 a.m., Daylight Saving Time begins in the United States.
During late Winter we move our clocks one hour ahead and "lose" an hour during the night and each Fall we move our clocks back one hour and "gain" an extra hour. But Daylight Saving Time (and not Daylight Savings Time with an "s") wasn't just created to confuse our schedules.
The phrase "Spring forward, Fall back" helps people remember how Daylight Saving Time affects their clocks. At 2 a.m. on the second Sunday in March, we set our clocks forward one hour ahead of Standard Time ("Spring forward," even though Spring doesn't begin until late March, over a week after the start of Daylight Saving Time). We "Fall back" at 2 a.m. on the first Sunday in November by setting our clock back one hour and thus returning to Standard Time.
The change to Daylight Saving Time ostensibly allows us to use less energy in lighting our homes by taking advantage of the longer and later daylight hours. During the eight-month period of Daylight Saving Time, the names of time in each of the time zones in the U.S. (map) change as well. Eastern Standard Time (EST) becomes Eastern Daylight Time, Central Standard Time (CST) becomes Central Daylight Time (CDT), Mountain Standard Time (MST) becomes Mountain Daylight Time (MDT), Pacific Standard Time becomes Pacific Daylight Time (PDT), and so forth.

Daylight Saving Time Around the World

Other parts of the world observe Daylight Saving Time as well. While European nations have been taking advantage of the time change for decades, in 1996 the European Union (EU) standardized a EU-wide European Summer Time. This EU version of Daylight Saving Time runs from the last Sunday in March through the last Sunday in October. In the southern hemisphere, where Summer comes in December, Daylight Saving Time is observed from October to March. Equatorial and tropical countries (lower latitudes) don't observe Daylight Saving Time since the daylight hours are similar during every season; so there's no advantage to moving clocks forward during the Summer.

Kyrgyzstan and Iceland are the only countries that observe year-round Daylight Saving Time.