In the 108-year history of daylight saving time in the United States, the country has three times moved to institute it year-round: during each of the two world wars and in 1973-74.

Now, after a 2022 attempt to reintroduce this policy floundered, the U.S. House of Representatives on July 14, 2026, passed the Sunshine Protection Act, which would put the country permanently on daylight saving time. The bipartisan bill passed by a wide margin, 308-117, with President Donald Trump publicly backing the measure. It will now be considered by the Senate.

With the exception of Arizona and Hawaii, which observe standard time year round, the U.S. observes seasonal daylight saving time, moving clocks ahead by one hour each March and turning them back each November.

Nearly two-thirds of Americans would like to eliminate changing the clocks twice a year, compared to 21% who aren’t sure and 16% who would like to keep moving their clocks back and forth, according to a 2026 poll.

But the effects go beyond simple inconvenience. Researchers are discovering that “springing ahead” each March is connected with serious negative health effects, including an uptick in heart attacks and teen sleep deprivation. In contrast, the fall transition back to standard time is not associated with these health effects, as my co-authors and I noted in a 2020 commentary.

I’ve studied the pros and cons of these twice-annual rituals for more than five years as a professor of neurology and pediatrics and the director of Vanderbilt University Medical Center’s sleep division. It’s become clear to me and many of my colleagues that the transition to daylight saving time each spring affects health immediately after the clock change and also for the nearly eight months that Americans remain on daylight saving time.

The strong case for permanent standard time

Americans are split on whether they prefer permanent daylight saving time or permanent standard........

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