The Senate on Tuesday unanimously passed a bill to make daylight saving time (DST) permanent—a move that many health experts have encouraged in recent years to prevent sleep disruptions and other health issues.

Senate approves bill for permanent DST

Just two days after most of the country switched over to DST, the Senate approved Sen. Marco Rubio's (R-Fla.) Sunshine Protection Act by unanimous consent. If enacted, the bill would make the recent time change permanent year-round. It is the latest attempt at a permanent DST since the 1970s, which was quickly reversed after public outcry.

According to Sen. Sheldon Whitehouse (D-R.I.), one of the bill's backers, the bill was intentionally introduced after this year's DST time change. "We did try and get it done once the clocks had just changed," he said. "Because it made it more timely."

Under the bill, the permanent time change would not be implemented until November 2023 to accommodate for certain industries in the transportation sector, such as airlines and trains, that have already set their schedules.

Although the bill was passed by the Senate, it must still be approved by the House and by President Joe Biden before becoming law. Currently, the office of House Majority Leader Steny Hoyer (D-Md.) said there are no immediate plans to vote on the DST bill, but the House Committee on Energy and Commerce recently met about the issue, and there is bipartisan support for it, NPR reports.

A permanent move to DST would likely be supported by most Americans. An Economist/YouGov poll from last fall found that 63% of U.S. adults said they wanted to eliminate the current biannual time changes, and that more people supported implementing DST permanently over standard time.

But some, including Sen. Roger Wicker (R-Miss.), have reservations on behalf of people in northern and midwestern states that would endure darker winter mornings—however, Wicker ultimately said, "I'm not going to stand in the way," Politico reports.

At least 18 states over the last four years have passed laws to permanently switch to DST, although federal law must be changed first to allow these state laws to be implemented.

Speaking on the new DST bill, Sen Patty Murphy (D-Wash.) said, "Americans want more sunshine and less depression."

How permanent DST could improve Americans' health

According to health experts, switching the clocks twice a year often leads to sleep disruptions due to a mismatch between the body's "biological clock," or circadian rhythm, which guides when people feel inclined to sleep or wake up, and the "social clock," which governs work or school schedules.

The resulting disruptions in sleep can impair health in many ways. For instance, experts have linked getting a good night's sleep with improved cognitive function and decision-making abilities, increased creativity, and more successfully regulated emotions, while a lack of sleep has been linked to inattention, poor focus, difficulty monitoring behavior, and decreased motor skills.

In addition, while sufficient sleep allows the body to heal and repair heart and blood vessels, decreased sleep has been linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, obesity, and stroke.

The change to DST in the spring is particularly disruptive and has been associated with increased health risks and consequences. For example, studies have found increased rates of ED visits and an increased risk of atrial fibrillation, depression, and suicide following daylight saving time. In addition, multiple studies have found that the spring DST change is associated with an increased risk of heart attack and stroke.

"It's a preventable cause of cardiac injury," said Muhammad Adeel Rishi, a pulmonologist and sleep clinic at Mayo Clinic Health System.

There's also evidence that fatal car accidents increase following a DST time change. A 1999 study from Johns Hopkins University and Stanford University found that the number of deadly accidents jumped to an average of 83.5 on the Monday after DST's "spring forward" compared to an average of 78.2 on a regular Monday. Similarly, a study published in Current Biology found that the risk of getting into a fatal car accident increased by 6% the week following a spring forward.

Overall, Erin Flynn-Evans, a consultant to the American Academy of Sleep Medicine's public safety committee, said that "[t]here's really no reason we should continue to do this back and forth [with the time changes]."

"The negative health consequences and the negative effect on multivehicular crashes in the spring are just not worth it," she added. (Adragna et al., Politico, 3/15; Hernandez, NPR, 3/16; Resnick, Vox, 3/15)