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Daylight Saving Time – DST – Summer Time

Daylight Saving Time, “Summer Time” or “DST” is a way of making better use of the natural daylight by setting the clocks forward one hour during the summer months, and back again in the fall.

An clock with the text change your clocks for DST.
Clocks go forward 1 hour in the spring.
Clocks go back 1 hour in the fall, and forward 1 hour in the spring.

Clocks back or forward?

The clock are set forward (= losing one hour) in the spring when DST starts, and back one hour (= regaining one hour) when DST ends in the fall. To remember which way the clock goes, keep in mind “spring forward, fall back”.

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.

Southern Hemisphere

(Australia, New Zealand, South America, southern Africa)

In the southern hemisphere (south of the equator) the participationg 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.

Where and when do the clocks change next?

Why use DST at all?

Many countries observe DST, and many don't. The difference in light is biggest in the areas that are furthest away from the equator.

Sunrise sunset times all over the world

Many countries use DST to make better use of the natural daylight in the evenings. Many people believe that DST could lead to fewer road accidents and injuries, by supplying more daylight during the hours more people are on the roads.

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.

Brief history of DST

Benjamin Franklin first suggested Daylight Saving Time in 1784, but modern DST was not proposed until 1895 when an entomologist from New Zealand, George Vernon Hudson, presented a proposal for a two-hour daylight saving shift to the Wellington Philosophical Society.

The conception of DST has also been credited to an English builder, William Willett in 1905, when he presented the idea to set the clocks forward during the summer months.

More history of DST

Not always 1 hour

Today claoks are almost always set one hour back or forward, 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) when it is on DST.

Topics: Daylight Saving Time, Time, March, November, October, Sun

In this Article


DST Library

  1. History of DST
  2. History of DST in Europe
  3. Your health and DST
  4. Controversy of DST
  5. 1 hour back or forward?
  6. Summer or Winter Time?
  7. Savings or Saving?

Daylight Saving Time

Daylight Saving Time worldwide

Sunrise & Sunset times

Current time worldwide

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