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.
Clocks Back or Forward?
“Spring forward, fall back” is one of the little sayings to hel p remember which way to set your watch. 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).
USA, Central America, Canada, Europe, Asia, northern Africa
Many countries in the Northern Hemisphere (north of the Equator) observe DST in the summer time, 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.
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 in the Southern Hemisphere starts in March–April and ends between September–November.
Why Use It 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.
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 clocks were set forward at 11 pm (23:00).
Not Always 1 Hour
Today clocks are almost always set one hour back or ahead.
Throughout history there have been several variations, like half adjustments (30 minutes) or double adjustment (two hours). Adjustments of 20 and 40 minutes have also been used.
In This Article
- Clocks Back or Forward?
- Northern Hemisphere
- Southern Hemisphere
- Why Use It at All?
- First Used in Germany
Daylight Saving Time – DST
- What is DST?
- One Hour Back or Forward?
- Savings or Saving?
- Pros and Cons of DST
- Your Health and DST
- Summer or Winter Time?
- History of DST
- History of DST in Europe
- US DST Changed in 2005
Time Zone Library
- What is a Time Zone?
- Half Hour & 45 Minute Time Zones
- What's the International Date Line?
- When Were Time Zones Introduced?
- USA Time Zones
- UK's Time Zones: GMT and BST
- Canada's Time Zones
- Australia’s Time Zones
- Antarctica's Time Zones