Why scientists say making daylight saving time permanent is a mistake

By Lauren Wilkin

The U.S. House of Representatives has voted to make daylight saving time permanent.

The Sunshine Protection Act means the United States would no longer have the clocks falling back in the fall and springing forward in the spring. Instead, there would be one permanent time zone.

Laura Bojarskaite, a neuroscientist and sleep researcher at the University of Oslo, has spoken out in favor of stopping the clock changes but has noticed one glaring issue with the American bill.

"The scientific consensus generally favors permanent standard time rather than permanent daylight saving time," Bojarskaite says.

"Standard time is more closely aligned with the sun, which means brighter mornings and earlier exposure to daylight — one of the strongest signals for synchronizing our internal biological clocks."

By permanently adopting daylight saving time, parts of America won't see sunrise until 9 a.m. — which could pose safety issues for children traveling to school.

How the clock changes impact our health

“The spring clock change, when we lose one hour of sleep, is the more problematic of the two transitions," Bojarskaite, the author of the best-selling book “300 Questions and Answers About Sleep,” explains.

"The clock change essentially creates a mild form of social jet lag. Our work schedules suddenly shift while our biological clocks remain on the old time.

"Even though one hour may sound trivial, our biological clocks are surprisingly sensitive to abrupt changes in timing.

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"Research has linked the days following the spring transition to shorter sleep, increased sleepiness, impaired attention, more workplace accidents and even small increases in cardiovascular events and traffic accidents.

"The fall transition tends to be easier because we gain an extra hour of sleep, but even then, many people experience temporary circadian disruption.”

For this reason, Bojarskaite says: "Eliminating the twice-yearly clock changes would be beneficial because our brains and bodies prefer stable timing cues."

Which time zone should the U.K. adopt?

Bojarskaite says the important question is which time should become permanent.

She believes there is far more evidence for adopting permanent standard time, arguing that early morning sun benefits both our mental and physical health.

“I think the discussion itself is a positive sign because it reflects growing recognition that circadian health matters," she says.

"However, if the goal is to improve public health and sleep, I would urge policymakers to consider the scientific evidence carefully."

"Most sleep and circadian organizations support ending the biannual clock changes, but they generally recommend adopting permanent standard time rather than permanent daylight saving time."

"The sun is the master clock for the brain. Policies that keep our social clocks more closely aligned with natural light are likely to be the healthiest option in the long term.”

But ultimately, Bojarskaite believes, “The healthiest clock is the one that changes the least,” so any policy change is welcome.