Daylight Saving Time

Daylight Saving Time (DST, also commonly referred to as Summer Time) is used in many locations around the world as a time adjustment to local clocks motivated by an effort take greater advantage of available natural light during the summer months.

The amount of the time shift varies, but one hour is the most common. The dates of the beginning and ending of DST also vary by country. In most DST countries in the Northern Hemisphere, however, clocks change forwards in spring, early on a Sunday morning at the end of March and change backwards early on a Sunday morning at the end of October. In the Southern Hemisphere, the beginning and ending dates are switched.

Daylight saving time is generally a temperate zone practice; day lengths in the tropics do not vary enough to justify DST.

In practice, the existence of Daylight Saving Time brings a country-specific, time-dependent correction to the standard time zone offset applied to a given location.