Daylight Saving Time Explained
Why the clocks change twice a year, who started it, and which countries still do it.
What daylight saving time is
Daylight saving time (DST) moves the clocks one hour forward in spring and back in autumn. Summer evenings get an extra hour of daylight, and mornings get one hour less. People remember it as "spring forward, fall back".
Who created it
Benjamin Franklin joked about Parisians saving candles by getting up earlier in 1784, but he did not propose changing clocks. The modern idea came from George Hudson in New Zealand in 1895 and William Willett in Britain in 1907. Germany was the first country to use it nationally, in 1916, to save fuel during the First World War. Britain and the US followed soon after.
When the clocks change
- United States and Canada: second Sunday in March at 2:00 AM, back on the first Sunday in November.
- UK and the EU: last Sunday in March, back on the last Sunday in October, at 01:00 UTC.
- Australia (south-east) and New Zealand: the reverse, because their summer is in December.
See the exact dates on our daylight saving time page.
Who does not change
Most of Arizona, Hawaii, and US territories such as Puerto Rico stay on standard time all year. Most countries in Asia and Africa, and those near the equator, do not use DST, because their day length hardly changes through the year.
The debate
Supporters point to brighter evenings and more time outdoors. Critics point to lost sleep, a short rise in accidents after the spring change, and little proof of energy savings. Several US states have voted for permanent DST, but it needs approval from Congress.
Questions
Do we gain or lose an hour in spring?
You lose an hour in spring, when 2:00 AM becomes 3:00 AM, and gain it back in autumn.
Why is it called daylight saving time?
Because it was meant to save daylight, and the fuel needed for lighting, by moving waking hours into the light evening.
Is it daylight saving or daylight savings?
The official term is daylight saving time, without the s, but "daylight savings" is very common in everyday speech.
By the TimeNowTools team · Last reviewed 20 October 2026