The term “daylight saving time” (DST) sounds like a good thing. (No one wants to waste daylight.) But in reality, it’s a misnomer: We don’t actually gain more sunlight by moving our clocks ahead each spring. And actually, this shift might not be the best move for our health. That’s according to the authority on sleep in the US: The American Academy of Sleep Medicine.
The debate around this topic comes up every year, like clockwork (see: exhausted parents and confused dogs). But it’s especially top of mind now after the US Senate recently passed a new bill aiming to put an end to changing the clocks and keeping DST permanent. But here’s the thing: Experts say it would make more sense to stay in standard time, instead — aka what we’re in from November to March. To understand why, we talked to Rebecca Robbins, a sleep researcher, instructor at Harvard Medical School, and co-author of “Sleep for Success!”
Back up: What is daylight saving time, actually?
Unless you live in Hawaii or Arizona, daylight saving time (no judgment if you call it “daylight savings”) is the time between the second Sunday in March and the first Sunday in November when American clocks are shifted forward by an hour. They ‘fall back’ to standard time in November. The practice was initially adopted in the US as a way to preserve energy and resources during World War I.
The plus side of DST: later sunsets. The downside: mornings are daaaaark. And these effects would show up even more during the winter, when the days are shorter.
What is the new daylight saving time bill about?
The Sunshine Protection Act, which recently passed the Senate, would make DST permanent. (Note: This name is pretty sus. So, again, it still doesn’t mean we get more light in total.) Thing to know: The US tried permanent daylight saving time before — most recently in 1974. But it lasted less than a year before the Senate voted to return to our current system.
How might a permanent daylight saving time affect my health?
A permanent DST would shift sunrises to an hour later during the times we used to switch to standard time. That would mean longer mornings in the dark, which could particularly be a problem for those living on the western edges of time zones. The delay in exposure to morning light could possibly throw off people’s natural circadian rhythms. Aka the internal clock that governs sleep and impacts plenty of other body functions, says Robbins. Note: Experts say our circadian rhythms are more closely aligned with standard time. "And one hour makes a difference,” Robbins said. “If you’ve ever traveled time zones, you can attest to this.”
She points to Utah as an example of a place where the later sunrise might have a pronounced effect. “They're at the very end of their time zone,” Robbins said. According to The Washington Post, some parts of Utah would see the latest sunrise of the year around 8:30 a.m. to 9 a.m. Some parts of Montana and North Dakota wouldn’t see sunrise until after 9:30 a.m.
Robbins said that night shift workers — who might be sleeping when the sun’s out and awake when it’s down — are the best examples of “how circadian misalignment can be so problematic.”
“We have scores of data to show that…those individuals are at extremely elevated risks for cardiovascular disease, diabetes, heart attacks, strokes, high blood pressure — just a host of adverse outcomes,” she says. Because when your circadian clock isn’t in sync with sunlight, it can throw off the timing of your natural body processes. For example: The circadian clock typically allows for blood pressure to dip at night. “If we don’t get that natural dipping at night, you’re gonna wake up with an elevated blood pressure,” Robbins said.
But in defense of a permanent DST, Sen. Marco Rubio, one of the bill’s sponsors, said in a press release that a big reason he supports the idea is to give kids more light for evening activities like outdoor sports.
Fair point. But while later sunsets might mean more light for outdoor activities, they also mean more light for your brain. Which starts prepping for sleep when the sun sets by producing melatonin — aka the sleep hormone. Robbins said this ideally happens about two to three hours before bed. A delay in that hormone production could cause problems with feeling sleepy at bedtime.
What if we made standard time permanent, instead?
That’s what the American Academy of Sleep Medicine (AASM) has suggested.
Reminder: Standard time is the one that makes sunrises and sunsets an hour earlier.
“Current evidence best supports the adoption of year-round standard time, which aligns best with human circadian biology and provides distinct benefits for public health and safety,” the AASM said in a statement after the Senate passed the Sunshine Protection Act.
And in case you need a reminder about why we’re talking about switching to any time permanently: That March ‘spring ahead’ (where we lose an hour of sleep), for many people, is the worst. The fatigue people have in the week after switching to DST has been associated with a spike in health-related incidents, from car accidents to heart attacks and strokes.
How can I get back on track if my circadian rhythm feels off?
If you’re concerned about getting enough shut-eye with a permanent daylight savings, here are a couple things to try: expose yourself to some kind of artificial light in the morning (think: a light box) and keep your environment dark in the evening (see: blackout shades). These can help your circadian rhythm stay on track, said Robbins. And here are things you can do during the day and right before bed to help get you primed for some quality Zzz’s.
Most people seem to agree that changing the clocks twice a year isn’t the best way to deal with shorter days. But while politicians have pushed to make daylight saving time permanent, sleep experts tend to think that standard time is the one that’s most in line with our body clocks. Because going an hour without morning sunlight could be harder on the mind and body than you might realize.
Skimm’d by Carly Mallenbaum, Anthony Rivas, Eleanor Goldberg, and Alicia Valenski
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