Last updated: March 2026
Daylight Saving Time FAQ
Answers to the most common DST questions
When does Daylight Saving Time start and end in the United States?
In 2026, DST starts on Sunday, March 8 at 2:00 AM and ends on Sunday, November 1 at 2:00 AM. The US follows the rule: second Sunday in March to first Sunday in November, established by the Energy Policy Act of 2005. Read more →
When do clocks change in Europe and the UK?
In 2026, clocks go forward on Sunday, March 29 and back on Sunday, October 25. The EU and UK use the last Sunday in March and last Sunday in October. The change happens simultaneously at 1:00 AM UTC across all participating countries. Read more →
Which countries observe Daylight Saving Time?
About 70 countries observe DST. The main participants are in North America, Europe, and parts of Oceania and South America. Most of Africa, Asia, and equatorial regions do not observe it. Read more →
Why do some US states not observe DST?
Hawaii and most of Arizona (excluding the Navajo Nation) have opted out of DST under the Uniform Time Act of 1966, which allows states to exempt themselves. Hawaii's proximity to the equator means day length barely varies. Arizona's hot climate means residents prefer more darkness in the evening, not more sun.
Does DST save energy?
Evidence is mixed. The original rationale was reducing artificial lighting, which saved meaningful energy when incandescent bulbs were standard. Modern studies show minimal savings — sometimes even increased energy use from air conditioning. A 2008 US Department of Energy study found the four-week DST extension saved about 0.5% of electricity per day.
How does DST affect health?
The spring transition (losing an hour) is associated with a temporary increase in heart attacks, workplace injuries, and car accidents in the days following the change. Sleep disruption typically lasts a few days for most people. The fall transition (gaining an hour) has fewer documented negative effects. The American Academy of Sleep Medicine has advocated for permanent standard time.
Will the US make DST permanent?
The Sunshine Protection Act passed the US Senate in 2022 proposing permanent DST, but the House did not vote on it. Several states have passed resolutions supporting permanent DST, but these require federal approval to take effect. As of March 2026, no federal legislation has been enacted.
Is Europe going to stop changing clocks?
The European Commission proposed in 2018 to abolish seasonal clock changes, with member states choosing permanent standard or summer time. The European Parliament voted in favor in 2019, but the Council of the EU has not reached agreement. The proposal is effectively stalled with no implementation date.
Why did Russia stop observing DST?
Russia moved to permanent summer time in 2011 but reversed to permanent standard time in 2014 after widespread complaints about dark winter mornings. President Putin signed the law citing public health concerns.
What happens to flight schedules during DST transitions?
Airlines adjust their published schedules to reflect local times. Since the US and Europe change clocks on different dates, there are typically 2–3 weeks each spring and autumn where the time difference between North America and Europe is one hour different than usual, affecting connections and scheduling.
When was DST first used?
Germany and Austria-Hungary were the first countries to adopt DST on April 30, 1916, during World War I, to conserve coal. The idea had been proposed independently by George Hudson (New Zealand, 1895) and William Willett (Britain, 1907). Read more →
What is the difference between DST and standard time?
Standard time is the base time for a given time zone. DST advances clocks by one hour from standard time. For example, Eastern Standard Time (EST) is UTC-5, while Eastern Daylight Time (EDT) is UTC-4. During DST, a location uses the "daylight" version of its time zone.
Last reviewed: March 2026. Data sources: official government publications and worldwideclock.com.