Daylight Saving Time – DST

Daylight Saving Time (DST) is the practice of setting the clocks forward one hour from Standard Time during the summer months, and back again in the fall, in order to make better use of natural daylight.

DST 2015  |  DST 2016

Clocks back or forward?

To remember which way to set your watch, keep in mind “spring forward, fall back”. You set your clock forward in the spring when DST starts (= lose one hour), and back one hour when DST ends in the fall (= regain one hour).

Northern Hemisphere

USA, Central America, Canada, Europe, Asia, northern Africa

Many countries in the Northern Hemisphere (north of the equator) observe DST, but not all. Daylight saving time is in use between March and April and ends between September and November as the countries return to Standard Time.

Where will DST start or end next?

Southern Hemisphere

Australia, New Zealand, South America, southern Africa

In the Southern Hemisphere (south of the equator) the participating countries start DST between September and November and ends between March and April. Standard time begins in the southern hemisphere between March–April and ends between September–November.

Why use DST at all?

Many countries use DST to make better use of the natural daylight in the evenings, and many don't. The difference in light is most noticeable in the areas close to the Poles, i.e. furthest away from the Earth's equator.

Some studies show that DST could lead to fewer road accidents and injuries by supplying more daylight during the hours more people use the roads. Other studies claim that people's health might suffer due to DST changes.

DST is also used to reduce the amount of energy needed for artificial lighting during the evening hours. However, many studies disagree about DST's energy savings and while some studies show a positive outcome, others do not.

DST first used in Germany

US inventor and politician Benjamin Franklin first proposed the concept of DST in 1784, but modern Daylight Saving Time first saw the light of day, in 1895 when an entomologist from New Zealand, George Vernon Hudson, presented a proposal for a two-hour daylight saving shift. However,

Germany was the first country to implement DST on April 30, 1916 when the clocks were set forward at 11 pm (23:00).

Not always 1 hour

Today clocks are almost always set one hour back or ahead, but throughout history there have been several variations, like half adjustment (30 minutes) or double adjustment (two hours), and adjustments of 20 and 40 minutes have also been used. A two-hour adjustment was used in several countries during the 1940s and elsewhere at times.

A half adjustment was sometimes used in New Zealand in the first half of the 20th century. Australia's Lord Howe Island (UTC+10:30) follows a DST schedule in which clocks are moved 30 minutes forward to UTC+11, which is Australian Eastern Daylight Time (AEDT) during DST.