This weekend, weary Halloween revelers across the U.S. will dutifully set their clocks to 鈥渇all back鈥� 鈥� signaling the end of daylight saving time for 2020. The annual ritual may give some people an extra hour of sleep on Saturday night, but for others, including parents of young children and shift workers, it鈥檚 an annoying complication that takes days of adjustment.
And is it really necessary? A growing body of evidence suggests that our twice-yearly tradition of changing our clocks to gain or lose an hour of morning sunlight isn鈥檛 just irritating: It鈥檚 actually dangerous. In the first days after the switch to daylight saving time in the spring, heart attacks and traffic accidents both increase.
Several states are now contemplating an end to daylight saving time. Last year, , which dates back to World War I and was presented as an energy saver (research, it鈥檚 worth noting, is 鈥溾��).
On Thursday鈥檚 St. Louis on the Air, Erik Herzog explained why scientists increasingly believe we need to scrap the time shifting. A professor of biology and neuroscience at Washington University, he focuses on understanding circadian clocks and their role in behavior and health.
鈥淲hat we experience is this shifting of the clock on the wall. Nothing in the world changes,鈥� he said. 鈥淭he only thing that's going to happen is we're going to ask everyone to somehow change their biology, which tells you when to wake up and when to go to sleep, to adjust to this social cue on the wall. And that鈥檚 a real challenge to our biology.鈥�
While 鈥渇alling back鈥� has been associated with positive things (including a reduction in car crashes in the days after the shift), the price we pay is true havoc in the spring.
鈥淲hen we spring forward, that loss of an hour of sleep is really challenging,鈥� Herzog said. 鈥淲e see things like three days of increased risk for car accidents, and three days of risk associations for heart attacks. 鈥� It鈥檚 one hour that cumulatively, over many days, can have a big impact on our health.鈥�
Many callers shared Herzog鈥檚 assertion that the time changes aren鈥檛 worth it. But some argued that we should actually shift permanently to daylight saving time, giving up some light in the morning in exchange for increased evening sunlight. Sen. Marco Rubio is , and Herzog noted that the golf lobby (yes, ) is a big fan.
But both the and the say morning is when we really need the sunlight.
鈥淥ur circadian clocks depend upon light to help us synchronize to the local light-dark schedule,鈥� Herzog said. 鈥淗aving light in the morning helps us align our biology to local time. If we鈥檙e forcing ourselves to wake up before sunrise, that turns out to be against our biology.鈥�
Herzog noted that when President Richard Nixon moved the U.S. to year-round daylight saving time in 1974, people hated it. It barely lasted a year.
鈥淭he popular demand was to get rid of it, and the practice was ended,鈥� he said. 鈥淭hey returned within a year to the switching.鈥�
鈥�鈥� brings you the stories of St. Louis and the people who live, work and create in our region. The show is hosted by and produced by , , and . The audio engineer is .
