Sleep and the Time Change: Surprisingly Harmful Ways DST Stresses the Body
Why it’s time to put an end to this nonsense
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Time change is coming.
If that sounds ominous annoying (dated reference to Game of Thrones aside), it’s because it kind of is. Don’t get me wrong, I’m a sun chaser, but Daylight Savings Time (DST) is pretty purposeless and SO unfriendly to our circadian rhythm. I’m one of THOSE people: Someone who believes the sun should set permanently (see what I did there?) on DST, and that Standard time should be the only time we set our clocks by.
It wasn’t always that way. When I was younger, I never really noticed the time change. It wasn’t something I thought about; it just happened, and you went about your day. As a child, I’m certain it was harder for my parents trying to get me and my sister out of bed when it felt like we should still get that 1 extra hour of sleep. We were always obnoxiously difficult to get out of bed, though; on the days we’d really drag our feet, my mom (the most chipper morning person to ever exist on this planet) would send in our teeny-tiny poodle who would jump, pounce, lick and, if she got really worked up, would poop on our beds … which of course would cause us to get up, because we’d have to clean it up.
Fast forward to being a 44-year old grown ass adult, and I’m SO over this time change nonsense. Over the last 2 years, that 1 hour shift has really become THE WORST. At least for a few days.
But, my desire to eradicate DST (yes, I’m using language more appropriate to an infestation or outbreak) isn’t because I find it annoying. No. It’s because our body’s and circadian rhythm are naturally synched to the rise and fall of the sun and moon. Changing the clocks doesn’t make it less of a fact, it just forces our bodies to adapt in ways that aren’t really beneficial to us. Pile on alllll of the other ways our circadian rhythms go off-kilter and our sleep and daytime energy are affected, and it’s just a dumpster fire waiting to happen. If “dumpster fire” is not to your liking, the technical term for the misalignment of social demands (like work, school, life) with our circadian rhythm is “social jet lag.”
Before I dig into why I think it should go away permanently and we should adopt Standard time forever more, let’s do a quick review of its history. And, I must say, it was an unexpected can of worms.
History of Daylight Savings Time: And, NO, it’s not because of Farmers
First, contrary to popular belief, DST was NOT established for the sake of farmers—they were (and still are) actually against it—nor was it an idea Benjamin Franklin came up with1,2.
It was first considered in New Zealand in the late 1800s2,3, supposedly, by an entomologist who proposed shifting the clocks by 2 hours from October through March, so he could have more prime bug-watching time during the summer months—what a novel and narcissistic way to solve a problem that existed for no one else. In the early 1900s, a British builder suggested an absurd and unrealistic time change of shifting the clocks 20 minutes ahead every Sunday in April (4 time changes in one month) and then shifting them back by 20 minutes every Sunday in September (another 4 time changes) for a whopping 8 times changes in the course of a year2. Seriously, my dude. WTH?
The time change as we know it came about during World War I. Germany led the effort around 1916 as a way to use less fuel for lighting and to have more resources available for the war effort1.
By 1918, the United States signed the Standard Time Act into law which included shifting clocks ahead by an hour to, you guessed it, save on energy costs during the war1,3,4. In fact, DST was once called “war time” for this reason. Once the war was over, the law was repealed, and clocks were rolled back (though Woodrow Wilson did his damndest to try to keep it around). Not to go too far down a rabbit hole, but the Standard Time Act also established the five timezones and standard time within the timezones3.
In 1942, World War II brought “war time” back—this time it got a more aggressive makeover. It wasn’t just noted as a way to save energy or conserve fuel, it was deemed a necessity to “promote national security and defense;” further, war time became a real thing as time zones were called Pacific War Time, Eastern War Time, and so on. Again, once the war ended, the law was repealed, and Standard Time was reinstated3.
Lest we believe Standard Time was universally and seamlessly accepted upon repeal of the Federal law at the end of World War II, it was left to each state to determine their own standard time1,4. And it became a real cluster-fuck, shit-show for the next 20 years with states and regions opting in and out of DST willy-nilly causing a real problem for the broadcast and transportation industries1,3,4.
While it might not be that important for people to get all of their TV shows, nightly news, and radio programs at all the same times, it is pretty important for airplanes and airports to function well.
So, as with any teenagers who party too hard or argue too much, Mom and Dad had to step in. In 1966, the Uniform Time Act was established with DST beginning in April and ending in October1,2. Only Arizona and Hawaii maintained their rebellious spirits, opting to maintain Standard Time year-round1.
Since then there have been various adaptations to the law that saw the time change start much earlier (as early as January in 1974 due the oil embargo, aka energy crisis4). It wasn’t until 2007, that lawmakers decided to begin DST on the second Sunday in March and end it the first Sunday in November.
There have been several starts and stops to do away with the time change, including most recently, in 2023, with the Sunshine Protection Act, which would make DST the new standard time.
Like I said, I’m a sun chaser. I actually really enjoy the longer days of summer. I used to loooove living in a place that didn’t get dark until 10 p.m. in the summer. I used to think anyone who wanted to make Standard Time permanent was just off their rocker. But it really is counterproductive for our chronobiology. So let’s dig into why.
Why Permanent Daylight Savings Time is a Terrible Idea
The government tried to go all-in on DST a couple times. As early as 1919, Woodrow Wilson tried to veto the repeal of the Standard Time Act3 (DST as a concept was contentious, even back then). Then, again, in 1974, when the energy crisis hit, DST was deemed THE TIME, but it was repealed when public support became incredibly low after experiencing the first winter of dark ass mornings1,5. Turns out waking up to dark mornings every day is much harder on mental wellbeing than any benefit the extra daylight hour imparted.
Research from sciences that study sleep, circadian rhythms, chronobiology, and health, in general, pretty much have reached consensus that permanently instituting DST is a terrible idea that will lead to a cascade of negative health outcomes.
Ultimately, light is the biggest regulator of circadian rhythm. Our biological rhythms are keyed to work in concert with the natural rise and fall of the sun and moon, which occurs as part of Standard Time. Daylight Savings Time has been compared to forced jetlag for the body. And, the transitions back and forth between Standard and Daylight Savings Time are actually pretty stressful on the body. The transitions into and out of DST are commonly associated with sleep disruptions, mood disturbances, and increased suicide5.
Transition from DTS to Standard Time: The Wrong Focus
Advocates in favor of permanent DST love to talk about the potential drop in serotonin levels from less sun exposure. This is one of the primary arguments made for why we should make DST permanent. But that argument falls apart pretty quickly.
It is true that sunlight may increase the brain’s release of serotonin (which, along with the Vitamin D benefits, is why I recommend people get early morning sun exposure before the heat from sun gets too hot). We feel this loss of daylight and the dip in serotonin and vitamin D most keenly in the winter months. Some of us experience Seasonal Affective Disorder. However, simply shifting daylight by an hour does not account for the naturally shorter days that occur that time of year, the inclement weather that is often responsible for lack of sunshine, or the colder weather that often prohibits people from being outdoors even if the sun is shining. It also assumes that people will prioritize being out in the sun in the evening (which if that happens as a post-meal brisk walk would actually be beneficial in addressing the rampant insulin resistance Americans experience). And, it dismisses the natural adaptations the body makes to seasonal day length and day light.
The argument in favor of permanent DST almost always focuses on the transition from DST to Standard time and, oddly, centers on the circadian rhythm disruption that occurs. I say “oddly” because it’s odd that they try to center the circadian rhythm disruptions from the transition, yet completely fail to acknowledge how out-of-rhythm permanent DST is with the natural chronobiology of our circadian rhythm. As if focusing on it for the transition period and then forcing it into permanent DST will somehow just magically reset it to coincide with the new DST normal. Sure, that could occur over generations of genetic adaptations … maybe. But it’s really more like jamming a square peg into a round hole and then being happy that the new not-quite-round shape continues to fit through the round hole.
Research has shown myocardial infarction risk may be elevated due to chronic effects of DST; further, cardiac events actually decrease after the shift from DST back to Standard5.
Transition from Standard to DST
A lot of attention in the advocacy to permanent DST focuses on the transition from DST back to Standard. However, the transition from Standard to DST actually may be more problematic. The Standard to DST one-hour spring forward has been associated with increased
Risk of myocardial infarction5
Risk of stroke5
Risk of hospital admissions due to acute atrial fibrillation5
Risk of cardiovascular morbidity5
Missed medical appointments5
Emergency room visits5
Return visits to the hospital5
Circadian misalignment5
The decreased day light and increased evening light are direct contributors to the increased circadian misalignment, which may also result in reduced quantity of sleep (sleep loss) and increased sleep debt5. The physiological stress inflicted to the body goes beyond sleep loss and sleep debt, it can cause cellular dysfunction, epigenetic changes, increased production of pro-inflammation biomarkers, and decreased vagal tone which can contribute to increased heart rate, increased blood pressure, and even greater reductions of sleep5.
Interestingly enough, even the stock market performance takes a hit the Monday after DST goes into effect5.
Impacts of Permanent Daylight Savings Time
Permanent DST does not actually consider the impacts to sleep, the natural circadian rhythm and melatonin-cortisol changes. These would contribute far more to negative health outcomes than a possible decrease of serotonin that may occur.
Natural circadian rhythms of our chronobiology adapt and flow with seasonal changes; DST on the other hand, results in more darkness in the morning and more light in the evening; the cumulative effects of early morning darkness and later evening light result in changes to hormone and neurotransmitter production that operate on a circadian rhythm—this goes beyond the cortisol-melatonin cycle and affects ALL process, hormones and neurotransmitters that are influenced by the circadian rhythm. Physiological effects and changes due to DST may take months to readjust; permanent DST may result in permanent phase delays5 (remember that square peg, round hole?).
A potential shift toward going to bed later and waking up later or, much more likely, simply going to bed later, getting less sleep and waking up far more tired (because work, school, kids, life may dictate our wake times), can translate into increased substance use and abuse, increased obesity, metabolic syndrome, depression, and cardiovascular disease … all of which are correlated with later sleep timing5.
What the Research Says
There’s actually not a lot of direct evidence on the chronic effects of DST, because we’ve not had long periods of DST in place. During seasonal DST, there is a modest decrease in afternoon motor vehicle accidents, which may correlate to more daylight hours (but causation is not established)5.
However, when the OPEC oil embargo, aka the energy crisis, occurred and DST was instituted in 1974 for a longer period of time (the added months of Jan-Apr), researchers found there were increased fatalities among school-aged children in the mornings, which may be due to the increased number of darker mornings during hours when children were traveling to school5. Again, this is a correlation, not causation. Additionally, a larger quantity of darker morning hours also means more colder, icier roads which means sleepier commuters driving for more collective hours in dark, inclement conditions1.
How to Adjust for the Time Change
The time change is inevitable, for now, at least. Some best practices you can use to help navigate the time change with ease are based in solid sleep hygiene practices.
What exactly is sleep hygiene?
It refers to practices that involve adapting your behaviors and sleep environment to contribute to adequate, quality sleep.
Poor sleep hygiene can negatively affect sleep quantity and quality.
Some signs for poor hygiene include having a hard time falling asleep, frequent sleep disturbances, daytime sleepiness, overall lack of enough sleep, and overall poor quality sleep.
Good sleep hygiene alone won't cure sleep conditions, like sleep apnea and insomnia, so, if you're concerned about those, be sure to speak to your doctor.
Good sleep hygiene won't guarantee perfect sleep, because it can't account for things like stress and anxiety, however, it does increase the likelihood of getting a great night's sleep.
So, what's involved in good sleep hygiene?
Going to bed and getting up around the same time every time day
Making sure your weekday and weekend bed time and rise times are within one hour of each other
A consistent bedtime routine
A dark bedroom (light in the bedroom is actually associated with a higher risk of diabetes)
A cool to cold bedroom
A quiet bedroom
Refraining from lengthy naps or naps in the late afternoon
Giving yourself at least 30 minutes to wind down
Limiting or stopping the use of digital devices 1 hour before bed
Ensure your last meal of the night is at least 2 hours before bed
Dimming the lights or using red lights 1 hour before bed
Limiting the activities you do in bed to sleep and sex; that means not watching TV, using your phone, or even reading in bed
Having a comfortable mattress and a high-quality pillow
Using clean, comfortable bedding
Having a clean, tidy bedroom free from dirt and offending odors
Limiting your tossing-and-turning time in bed; if you toss-and-turn or lie awake for more than 20 minutes, get out of bed and try stretching, reading, doing a yoga nidra or something else tin low light that encourages activation of the parasympathetic, rest and digest, nervous system.
Sleep hygiene activities (and managing the circadian rhythm) aren't limited to bedtime habits; daytime habits count, too. Things like getting adequate daylight exposure, being physically active, reducing or eliminating alcohol consumption, and cutting down or cutting out caffeine in the afternoon and evening. Yes, that daylight exposure is important, but it’s most favorable in the early morning. Again, this is great for both serotonin and Vitamin D prior to the sun getting too hot where you then may risk sunburn or skin damage.
I know this sounds like a LOT. You don't have to do EVERY. SINGLE. THING. But the more of these you incorporate, the better chance you'll have of setting yourself up for good, solid quality sleep.
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References
1 The History of Daylight Saving Time. https://www.colorado.edu/coloradan/2022/11/07/history-daylight-saving-time
2 A short history of daylight saving time. https://spectrumlocalnews.com/nc/charlotte/weather/2021/02/24/why-daylight-saving-time-
3 Daylight Saving Time Once Known As 'War Time'. https://www.defense.gov/News/Feature-Stories/story/Article/1779177/daylight-saving-time-once-known-as-war-time/#:~:text=In%20America%2C%20daylight%20saving%20time,zones%20that%20we%20now%20know.
4 Daylight Saving Time. https://aa.usno.navy.mil/faq/daylight_time
5 Daylight saving time: an American Academy of Sleep Medicine position statement. https://pmc.ncbi.nlm.nih.gov/articles/PMC7954020/