End of daylight saving time this weekend correlated with car crashes, heart attacks | November 10, 2023 | Almanac | Almanac Online |


News - November 10, 2023

End of daylight saving time this weekend correlated with car crashes, heart attacks

Despite the extra hour of sleep, experts say the time change doesn't have any positive impact on our health

by Isha Trivedi

This Sunday, Nov. 5, marked the end of daylight saving time. But what does that actually mean, and why are we still changing our clocks twice a year?

On the second Sunday of every March, we set our clocks one hour ahead and lose one hour of sleep — entering daylight saving time, where our days feel longer with the sun rising later in the day and setting later in the day. But on the first Sunday of every November, we set our clocks one hour behind and daylight saving time ends.

The legislation behind daylight saving time

While large swaths of North America still abide by the twice-per-year time change, a recent effort to eliminate the bi-annual changes has sparked conversation about the benefits and disadvantages of this disruption to our routines.

California voters first approved an initiative to establish daylight saving time back in 1949. While every state except for Hawaii and Arizona currently abide by daylight saving time, in 2018 former Assemblymember Kansen Chu, D-San Jose introduced a bill that would put California in permanent daylight saving time, meaning the sun would rise consistently later and set consistently later.

But despite widespread support from Californians, the legislation hasn't gotten the support it needs from federal lawmakers to actually go into effect.

The Sunshine Protection Act also attempted in 2018 to make daylight saving time permanent, and the Senate even approved the bill in March 2022 with plans to implement it this month. But the legislation has since lost steam and fizzled in the House.

The health impacts of daylight saving time

Rafael Pelayo, a sleep specialist with the Stanford Sleep Medicine Center, said daylight saving time actually has no health benefits, as the sudden addition or elimination of an hour from our days typically leads to an increase in car accidents and heart attacks every year.

"We're really a sleep-deprived country to begin with, so you're robbing an hour of sleep from people who don't have that hour to spare," he told this publication, referring to the spring start of daylight saving time.

In fact, the California Department of Fish and Wildlife issued a bulletin Friday, Nov. 3, encouraging drivers to exercise caution when driving on state roads and highways after the time changes this weekend, given the annual spike in vehicle and wildlife collisions associated with it every November.

"As drivers adjust to less daylight during the evening commute during the first week of November, please understand this is also the time of year that deer, elk, bears and other animals are typically on the move for migration, mating or foraging," the bulletin reads.

Pelayo said in the face of the obvious negative health impacts of daylight saving time, it's largely those in the commerce industry who support keeping it — those who benefit financially from consumers having more time in their days to spend money on optional expenses.

"People think we'll go shopping more, spend more time in retail if when they get out of work there's more light," he said.

He said even the Sunshine Protection Act would have negative health impacts because it would put us in constant daylight saving time with darker mornings. An earlier attempt to do so in the 1970s led to an increase in children dying in car crashes while waiting for school buses in the dark, he said.

"The American Academy of Sleep Medicine, the California Sleep Society and other health organizations propose that we just stay in permanent standard time, or standard real time, which makes biological sense," he said.

Pelayo said Californians should keep in mind that young children and pets won't be aware of the time change, and we should keep an extra eye on them this time of year.

"So even though the clock is changing, your animals are still going to want to get walked at the same time and will be active at the same time as before," he said. n


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