Why does daylight saving time exist?
Daylight saving, which began as a wartime energy‑saving measure, starts on Sunday, March 8, and ends on Sunday, November 7, 2026.
The ritual of changing the clocks twice a year to get more daylight has been in place for more than 50 years. But debates in state legislatures and Congress show that there’s interest in stopping the process.
When does daylight saving time start and end?
In 2026, daylight saving time starts on Sunday, March 8, and will end on Sunday, November 1. It will begin again on Sunday, March 14, 2027, and run through Sunday, November 7, 2027.
Why did daylight saving time begin in the US?
Daylight saving time was originally implemented in 1918 to help conserve fuel and power during World War I. Working during the sunlight hours meant burning less fuel, and the ability to work later into the day. The Standard Time Act of 1918, which established the time change, also established the nation’s official time zones.
Congress repealed daylight saving time after WWI ended. It was enacted again in 1942 during WWII and repealed in 1945.
The daylight saving procedures most people are familiar with came about in 1966 with the passage of the Uniform Time Act, which re-established the twice-yearly time change.
The most recent change to how Americans “save” daylight was 2005's Energy Policy Act. This act extended daylight saving a few weeks, beginning the second Sunday of March, and ending on the first Sunday in November.
Which states have daylight saving time?
As of 2026, 48 states and Washington, DC, participate in daylight saving time.
If states do not want to change their clocks twice yearly, they can opt to remain on standard time permanently, as Arizona and Hawaii do. States cannot, however, permanently opt for daylight saving time.
In 2006, Indiana became the 48th state to fully recognize daylight savings. It had previously exempted counties in the eastern time zone [Annotation: 80 of Indiana’s 92 counties are in the eastern time zone.] from observing daylight savings.
19 states have laws or resolutions to move to daylight saving time permanently.
Permanent daylight saving time legislation/resolutions or opt-outs, January 2026
Nineteen states have passed laws or resolutions to observe daylight saving time permanently, the most recent being Texas passing legislation supporting year-round daylight savings in 2025. However, these can only take effect if Congress were to change federal daylight saving time law.
To that end, on the federal level, the Sunshine Protection Act, which would move the US to permanent daylight saving time, has been introduced to Congress several times since 2018. It was introduced again in 2021 where it passed in the Senate but died in the House, and was introduced again in 2025.
Are there benefits to daylight saving time?
The Congressional Research Service (CRS) provided a report to Congress in 2020 that summarized various research studies about the effects of Daylight Savings Time that included:
- A 1974 Department of Transportation (DOT) Transportation Department study on daylight saving time found no conclusive difference in energy usage, crime, travel times, or trade during the time shift.
- A separate Transportation Department report was inconclusive on whether the practice led to more traffic fatalities with school children.
- In 2008, an Department of Energy (DOE) study showed energy consumption dropped 0.02% due to daylight saving time. The study also showed no “measurable impact” on vehicle gas consumption.
- An academic study published in 2020 found evidence of increased risk of heart attack during transitions to or from daylight saving time.
What parts of the US get the most daylight during working hours?
The amount of daylight varies by location. Northern cities get more dark days in the winter and more sunlight in the summer due to the Earth’s axis relative to the sun. Plus, the further west a city is in a time zone, the later its sunrises and sunsets will be.
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