Senators Introduce ‘Lock the Clock’ Bill to Make Daylight Saving Time Permanent

Commuters walk through the bright morning sunlight coming from windows in Grand Central Terminal in New York City, on March 11, 2019. Timothy A. Clary/AFP via Getty Images

A bipartisan group of senators, led by Sen. Rick Scott (R-Fla.), has reintroduced legislation to make daylight saving time permanent year-round. The proposal is opposed by a coalition of sleep medicine organizations, which advocate for “locking the clock” but in standard time mode.

The legislation, called the Sunshine Protection Act, was unanimously passed in the Senate in 2022 during the 117th Congress but it stalled in the House. Now, Scott and 15 other senators have re-introduced the bill, describing it as a common-sense approach that will simplify the lives of U.S. households, citing President-elect Donald Trump’s backing for an end to the practice of twice-yearly clock changes.

“I hear from Americans constantly that they are sick and tired of changing their clocks twice a year – it’s an unnecessary, decades-old practice that’s more of an annoyance to families than benefit to them,” Scott said in a Jan. 8 statement. “I’m excited to have President Trump back in the White House and fully on board to LOCK THE CLOCK so we can get this good bill passed and make this common-sense change that will simplify and benefit the lives of American families.”

While Trump has advocated for locking the clock, it’s unclear whether the president-elect is in favor of making daylight saving time or standard time permanent. In March 2019, he said he was fine with making daylight saving time permanent. In December 2024, he called for the elimination of daylight saving time, suggesting it’s standard time that he backs, a position aligned with several medical organizations.

The legislation proposed by Scott and the others would establish permanent daylight saving time, meaning clocks would no longer be turned back in the fall, resulting in later sunrises and sunsets throughout the winter. Current federal law allows states to exempt themselves from observing daylight saving time, with Arizona and Hawaii observing year-round standard time, resulting in more morning daylight in the winter months.

Advocates for permanent daylight saving time argue it would eliminate the need to turn clocks back in the fall and provide extended sunlight in the evening, offering more opportunities for outdoor activities.

“Every winter folks in Washington state despair at the prospect of losing an hour of precious sunlight when we are forced off Daylight Saving Time,” Sen. Patty Murray (D-Wash.) said in a statement. “This is about public health, it is about our economy, and it’s about just putting a little more light in families’ lives so they can spend time together, outdoors, in the sunshine.”

Opponents of daylight saving time, such as the American Academy of Sleep Medicine (AASM), counter that standard time is better for both health and safety. AASM explains in a position statement issued on Jan. 1 that there are numerous benefits to a permanent switch to standard time, including better sleep, less stress, and fewer car accidents.

The AASM position, which is endorsed by nearly two dozen organizations including including the American College of Chest Physicians and the National Safety Council, argues that standard time aligns more closely with the daily rhythms of the body’s natural clock. The groups say that increasing exposure to morning darkness and evening light—which is what daylight saving time does—harms sleep-wake patterns.

“Permanent, year-round standard time is the best choice to most closely match our circadian sleep-wake cycle,” said lead author of the AASM’s position statement, Dr. M. Adeel Rishi, pulmonology, sleep medicine, and critical care specialist at the Mayo Clinic in Eau Claire, Wisconsin. “Daylight saving time results in more darkness in the morning and more light in the evening, disrupting the body’s natural rhythm.”

Research cited by the AASM highlights acute health impacts of daylight saving time, including a higher risk of strokes, increased hospital admissions, and elevated inflammatory markers, which indicate stress on the body. The group also references studies showing that traffic fatalities increase by as much as six percent in the days following the switch to daylight saving time, and human error-related medical events rise by 18 percent in the first week.

Some research cited in the position statement suggests an increase in fatalities among school-aged children during daylight saving time, likely due to low-light conditions in the morning when children are traveling to school.

Although the AASM’s position statement outlines a range of adverse impacts associated with daylight saving time, it also highlights the harmful effects of the twice-yearly transitions, linking them to sleep disruptions, mood disturbances, and even an increased incidence of suicide.

The AASM position statement also acknowledges a report suggesting that daylight saving time may be associated with decreased crime rates due to increased evening light. The group notes that several other studies have indicated a modest decrease in the risk of car accidents.

However, the AASM argues that the preponderance of evidence indicates the chronic effects of daylight saving time are detrimental to human physiology, health, performance, safety, and even the economy.