July 15, 2026
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Making daylight saving time permanent all year runs counter to the body's natural rhythms, medical experts say,
President Donald Trump's wish to make daylight saving time permanent year round has made headway with the House, which passed the "Sunshine Protection Act" on Tuesday.
The bill would stop the twice-yearly clock changes for the entire country, fixing all 12 months of the year in daylight saving mode. The legislation now goes to the Senate, but some Republican lawmakers have said they will oppose it, the New York Times reported.
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Daylight saving time is when the clock moves ahead an hour during the warmer months to extend the amount of evening sunlight. But standard time, observed in the fall and winter, is more in line with the body's natural circadian rhythms, experts say.
The "medical community in general has voiced support for permanent standard time," Dr. Zhikui Wei, a specialist in sleep medicine and neurology at Thomas Jefferson University's Sleep Disorders Center, told PhillyVoice in 2024.
The American Academy of Sleep Medicine published a position paper in 2020 arguing that "an abundance of accumulated evidence indicates that the acute transition from standard time to daylight saving time incurs significant public health and safety risks, including increased risk of adverse cardiovascular events, mood disorders, and motor vehicle crashes."
Wei said it can take people "weeks to months to adjust to the lost hour" after clocks push ahead during daylight saving, resulting in "ongoing sleep deficiency."
Disrupted sleep increases risk of anxiety and depression, and research has found a link between the switch to daylight saving time and an increase in suicide deaths among men. Daylight saving time also is associated with a slight increased risk of heart attacks and strokes.
A 2015 study also found that students had shorter attention spans and slower reaction times in the days following the switch to daylight saving.
"Morning light is an environmental cue to set our body's internal clocks and promote alertness," U.S. Rep. Mary Gay Scanlon, a Democrat who represents Delaware County, said on the House floor Tuesday. "And dim evening light tells our bodies it's time to sleep."
Scanlon opposed the Sunshine Protection Act and supported a different bill earlier this month that would make standard time year-round.
Advocacy groups, such as the Coalition for Permanent Standard Time, also oppose the Sunshine Protection Act.
