The deadline for daylight saving time to become permanent in 2026 is approaching, but scientists say this change could be a mistake.
As Nov. 1 approaches, the Sunshine Protection Act remains stalled in the Senate. Unless Congress acts soon, Tennesseans will once again set their clocks back an hour when daylight saving time ends this fall.
The change in law has the backing of President Donald Trump, who has been vocal about the need for permanent daylight saving time.
"People are sick and tired of having to change their clocks twice a year," Trump wrote, arguing permanent daylight saving time would give people more daylight in the evening.
"In other words, leave it as it is now, and never change again," he wrote. "LET'S PASS THE SUNSHINE PROTECTION
ACT, ASAP."
Alongside the president's insistence that daylight saving time become permanent, a new report echoes a chorus of scientific research saying that permanent standard time is the best solution for eliminating the dreaded twice-yearly clock change.
Daylight saving time might be more enjoyable for its later sunsets year-round, but standard time's earlier sunrises align more with our body clocks, the report says. Permanent standard time could lead to better sleep and overall moods.
The new analysis examines the health effects of permanent standard time versus permanent daylight saving time. While the analysis is based in Canada, co-author Ralph Mistlberger noted that it also applies to the United States, as much of the included research was done there.
Both choices have pros and cons. Analysis shows that permanent daylight saving time keeps evenings lighter. This can help with recreation, social activities, commuting, and some types of economic activity. However, it also pushes sunrise back an hour, meaning more people wake up, travel to school, and commute to work in the dark on the coldest winter days.
Permanent standard time keeps more light in the morning and better matches our body clocks, but it makes evenings darker earlier.
Why experts say standard time is better for your health
Twice-yearly time changes are associated with negative health impacts, and springing forward is generally worse on our bodies than falling back, Erik Herzog, a professor of biology and neuroscience at Washington University in St. Louis, previously told USA TODAY.
The shift in spring is associated with an increase in heart attacks, and car accident rates also go up for a few days after, he said. Ending time changes would be good for health, but which year-round time is chosen matters.
The authors of a study in the Canadian Medical Association Journal, published on Oct. 5, say that making daylight saving time permanent could harm our body's internal clock. They warn that children and teenagers are at greater risk. As young people go through puberty, their natural sleep patterns shift later, but they still need to get up early for school.
Shifting evening light can help social events and businesses that get more customers at night. However, it makes it easier to stay up late and harder to wake up early, while morning commitments remain unchanged. This leads to something called "social jet lag." According to Mistlberger, social jet lag and not getting enough sleep can cause various health problems, including chronic illnesses, mood disorders, and even cancer.
Changing the morning light makes people get up and get ready for work in the dark. Children walk to school or wait for buses when it is hard to see.
A September report by K12 found that if the nation switched to permanent daylight saving time, 94 out of the 100 largest school districts would have students starting school in the dark during winter mornings. On average, students would travel to school in the dark on 117 days each winter. This compares with 77 days under the current time changes and only 35 days if the country adopted permanent standard time.
Why did daylight saving time start?
Simply put, World War I caused daylightsaving time. It began in Europe to conserve fuel for electricity. Germany and Austria enacted it first, and it then spread to 11 other countries. The United States did not adopt it until 1918, when it first observed daylight saving time on March 30. It was so wildly unpopular that it was repealed in 1919.
Daylight saving time was reintroduced during World War II. A major issue was that the federal government did not regulate it, and states and localities operated on different schedules. This schedule lasted from 1945 to 1966.
The Uniform Time Act of 1966 established specific dates for the start of daylight saving time. It was scheduled to begin on the last Sunday in April and to end on the last Sunday in October. States could pass laws prohibiting participation.
Daylight saving time as we know it today emerged after the turn of the century. The Energy Policy Act of 2005 extended daylight saving time to begin on the second Sunday of March and end on the first Sunday of November.
Was daylight saving time ever permanent before?
There was an attempt at making daylight saving time permanent in the 1970s, but the concept was repealed after two years because of its unpopularity. Many Americans were unhappy about having to drive to work and school in the dark every morning, which was the consequence of having more light in the evenings.
The idea may be more ideal now that more Americans work from home and don't have to worry about driving to work before the sun is up, even though most people already do. Americans typically start their workday between 6 and 9 a.m., meaning that in December and January, most people are on the road and in the office by the time the sun is coming up.
How sunrise and sunset times would change in Tennessee under permanent daylight saving time
Using the winter solstice, Dec. 21, as an example, here's how sunrise and sunset times would look on the shortest day of the year across major Tennessee cities if daylight saving time were observed year-round.
Chattanooga
- Current sunrise, sunset: 7:45 a.m. / 5:33 p.m.
- Under permanent daylight saving time: 8:45 a.m. / 6:33 p.m.
Clarksville
- Current sunrise, sunset: 6:57 a.m. / 4:37 p.m.
- Under permanent daylight saving time: 7:57 a.m. / 5:37 p.m.
Knoxville
- Current sunrise, sunset: 7:42 a.m. / 5:25 p.m.
- Under permanent daylight saving time: 8:42 a.m. / 6:25 p.m.
Jackson
- Current sunrise, sunset: 7:01 a.m. / 4:45 p.m.
- Under permanent daylight saving time: 8:01 a.m. / 5:45 p.m.
Memphis
- Current sunrise, sunset: 7:04 a.m. / 4:52 p.m.
- Under permanent daylight saving time: 8:04 a.m. / 5:52 p.m.
Nashville
- Current sunrise, sunset: 6:54 a.m. / 4:36 p.m.
- Under permanent daylight saving time: 7:54 a.m. / 5:36 p.m.
19 states passed laws to make daylight saving time permanent
In total, 19 states have enacted laws to make daylight saving time permanent, but these laws cannot go into effect until Congress allows it at the federal level. Some states have led the way on daylight saving time legislation, such as Florida, which passed the nation's first law of its kind in 2018.
Others followed in the ensuing years. In 2026, 16 states introduced 23 bills concerning daylight saving and standard time, according to the National Conference of State Legislatures. Under current federal law, states can opt to observe permanent standard time, as Arizona and Hawaii have, but cannot do the same with daylight saving time.
- Alabama
- Colorado
- Delaware
- Florida
- Georgia
- Idaho
- Louisiana
- Maine
- Minnesota
- Mississippi
- Montana
- Oklahoma
- Oregon
- South Carolina
- Tennessee
- Texas
- Utah
- Washington
- Wyoming
When will Congress vote on permanent daylight saving time?
If Congress is going to stop Americans from changing their clocks on Nov. 1, time is running out.
The Senate returned to Washington on Sept. 14 after a five-week recess, but the Sunshine Protection Act wasn't scheduled for a vote. Another congressional recess began Oct. 5.
That means Americans are increasingly likely to find themselves doing something many hoped would be a thing of the past: turning their clocks back an hour on Nov. 1.
USA TODAY contributed to this report.
Jordan Green covers trending news for The Commercial Appeal and Tennessee. She can be reached at jordan.green@commercialappeal.com.
This article originally appeared on Memphis Commercial Appeal: Scientists warn permanent daylight saving time could bring problems
