Daylight saving time ends this Sunday, Nov. 6,[1] for most of the US. Except for Arizona and Hawaii, every state in the US will roll clocks back an hour this weekend.

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 some interest in stopping the process.

At least 45 states have considered or passed legislation to shift to permanent daylight saving time or permanent standard time. And this year the Senate passed the Sunshine Protection Act, which would move the US to permanent daylight saving time. But the bill has not received a vote in the House of Representatives.

Why do we have daylight saving time?

Time zones in the US began in the late 1800s to help railroad companies coordinate along time and to reduce the likelihood of trains crashing due to differences in how time was kept.

The government didn’t alter time zones until 1918, with the passage of the Standard Time Act of 1918. At that time, the Interstate Commerce Commission, which regulated railroads at the time, was put in charge of time zones.

In 1918, the agency started the first instance of daylight saving time in the US to help conserve fuel and power during World War I. The idea was that shifting time to get more daylight hours would reduce the need for lighting. After the war’s conclusion, daylight saving time was abolished nationally, with some states continuing the practice.

It wasn’t until the founding of the Department of Transportation in 1966 that our modern version of daylight saving time began. The dates for when the US springs forward (the second Sunday of March) into daylight saving time or falls back (the first Sunday of November) to standard time are enshrined in federal law and were most recently changed in 2005.

Are there any places not following daylight saving time?

States are allowed to exempt themselves from daylight saving time but can’t set their schedules to permanent daylight saving time. As of 2022, Arizona and Hawaii are the only states to exempt themselves from daylight saving time.

Eleven states have passed laws to observe permanent daylight saving time. Arkansas and Georgia passed resolutions in support of permanent daylight saving time.

Earlier this year, the Senate unanimously passed the Sunshine Protection Act, which would move the US to permanent daylight saving time. However, the bill has not received a vote in the House of Representatives.

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Are there benefits to daylight saving time?

In the years since the formal adoption of seasonal daylight saving time, there’s been several studies into the impacts of the practice.

In 1974, a Department of Transportation study into the effects of daylight saving time found no conclusive difference in energy usage, on crime, travel times, or trade during the time shift. A separate report on whether the practice increased traffic fatalities involving school children was inconclusive.

In 2008, a Department of Energy study showed energy consumption was reduced by 0.02% due to daylight saving time. The study also showed no “measurable impact” on vehicle gas consumption.

An academic study cited in a report by the Congressional Research Service found evidence of some increase in heart attacks during transitions to or out of daylight saving time.

What parts of the US get the most daylight during working hours?

One goal of daylight saving time is to reduce the number of days with fewer hours of daylight during working hours.[2]

The amount of daylight an area gets in the US differs quite a bit based on where it’s located. Cities in the northern reaches of the US tend to get more dark days, or days with less than 10 hours of daylight in a year. Where a city is located in a time zone matters too. Sunrises and sunsets are later the further west a city is located in a time zone, for example. Daylight saving time has an impact on when those daylight hours occur, whether daylight is more during working hours or not.

Shifting to permanent daylight saving time would hit some cities more than others. A place like Bangor, Maine would have 98 more sunrises after 7 a.m. if it was on permanent daylight saving time. But Washington, DC, which is further to the west than Bangor, would get 44 more sunrises after 7 a.m.

Learn more about temperatures, precipitation, and more with USAFacts' Climate in the United States feature.


Correction: The original article had the incorrect date for when daylight saving time ends.


Clarification: The original article wasn't clear that daylight saving time affects when daylight is experienced, not the literal hours of daylight.

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