US House Backs Permanent Daylight Saving Time as Sleep Experts Flag Health Risks

The US House of Representatives has passed the Sunshine Protection Act, a bill that would move the country to permanent daylight saving time. If the Senate clears the measure after members return from recess on September 14, the twice-yearly ritual of moving clocks forward and back by an hour would end for the more than 330 million Americans who live in areas that observe daylight saving time.

President Trump has backed the proposal, though some Republican senators have not committed to it.

Beyond the politics, the change raises questions about sleep and health. Megan Petrov, an associate professor at Arizona State University's Edson College of Nursing and Health Innovation, is a clinical psychologist and sleep scientist whose lab studies how sleep and circadian rhythms shape chronic disease across a person's life. She supports ending seasonal clock changes but argues that the bill picks the wrong option.

"Permanent standard time is better aligned with human circadian biology," she said. In her view, permanent daylight saving time does not create an extra hour of daylight; it borrows an hour from the morning and pushes it into the evening, delaying the body clock and encouraging later bedtimes.

Morning light, she explained, is what synchronises the body's internal clock so that hormones and other signals arrive at the right time. Without it, the gap between the clock on the wall and the sun widens, and the effects accumulate over the year.

Petrov said the spring shift already costs about an hour of sleep in March and affects everyone, but some groups are more vulnerable. Children and adolescents, who are biologically inclined to sleep later, face a tougher adjustment when they still have to rise for school. Older adults and people at greater health risk are more prone to heart attacks and strokes in the morning, while commuters face a higher chance of traffic accidents.

Teenagers, she added, would be hit hardest by permanent daylight saving time. They are already among the most sleep-deprived groups in the country, and more evening light would push their bedtimes even later without any change to school start times, leaving many to travel to school in the dark.

To soften the impact of the existing spring and fall shifts, Petrov suggests adjusting sleep schedules gradually in the days beforehand and seeking morning light, which helps the body adapt faster. She stressed that sleep is vital for memory, decision-making and long-term health, and that the debate is not purely political or economic.