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Why Many Hate the Switch Back From Daylight to Standard Time

It’s not the one hour but the switching back and forth that causes problems.

Regrets from constantly changing the clock

Contrary to what boosters would have you believe, changing the clock does not magically squeeze out extra daylight. It merely shifts the hour—according to the clock—of sunrise and sunset. This has consequences because it disrupts the body’s inherent timekeeper, known as the circadian rhythm.

Growing evidence indicates that the twice-yearly time shifts are bad for one’s health. They not only disrupt sleep but might also increase the incidence of heart attacks, strokes, vehicle crashes, work injuries, miscarriages, depression, and suicide.

I wrote earlier here about the health perils associated with the “spring forward” to Daylight Saving Time, how it fights against our natural circadian rhythm, and why it is particularly annoying for those who chronically don’t allow themselves enough sleep. Here, I examine the downside of switching back to Standard Time.

Switch back to Standard Time–ugh!

A Danish study found an 11% increase in clinical depression after the time change, with symptoms slowly dissipating only after 10 weeks. An Australian study found that suicide rates in men increase after both the spring and fall time shifts. JAMA Neurology just published a paper called, “Are Daylight Saving Time Changes Bad for the Brain?”

Left to itself, the body knows what time it is because we evolved over 200,000 years on a rotating planet that has distinct periods of light and dark. This is true even as the seasons change and shift their relative proportion of light and dark. When politicians meddle with the clock, people find it hard to adjust.

That’s because every physical function down to the rate at which cells divide works in tempo with the master circadian clock. The body operates on timed cycles, from the release of hormones to modifying body temperature to whether our thinking is sharp or fuzzy. Sleep is linked to all of these.

3 time measures the brain must keep track of

The brain and body actually have to contend with three separate measures of time: sun time, or the hours of light and dark within a day; biological cycles that govern everything from urine output and potassium excretion to alertness and the ability to concentrate; and societal schedules for work, school, recreation, and socialization.

Anywhere in the world at noon local time, the sun is directly overhead. This accords with the conventions of Standard Time, which better aligns with the natural circadian clock, the sun clock, and the social clock. During Daylight Saving, clock time changes while the dark-light cycle doesn’t, forcing a discrepancy between your biological clock and the social one. It essentially puts you in another time zone without changing the day-night cycle, an induced kind of jet lag, if you will.

More than 60% of the world’s countries use Standard Time all year long. Most European countries are on Standard Time for five months of the year and spend the other seven months on Daylight Saving Time. The situation is even more lopsided in the U.S. and Canada, where Standard Time lasts a mere four and a half months.

A 2019 survey by the Associated Press and the Center for Public Affairs Research found that 31% of the population would like to stay on year-round Daylight Saving Time whereas 40% prefer sticking solely with Standard Time.

pasja 1000/Pixabay
What time is it, really?
Source: pasja 1000/Pixabay

Is it any wonder people get so riled up about the issue?

Should there be a law against Daylight Saving Time?

Federal law dictating that clocks move ahead one hour ahead in spring and an hour back in the fall dates to 1918. It almost doesn’t matter which one we pick as long as we choose one and stop switching. It is the switching back-and-forth that causes problems.

In the past three years, nine state governments passed legislation to remain on Daylight Saving Time permanently, although such a change can’t be made without congressional approval. Senator Marco Rubio introduced the Sunshine Protection Act even though Spring Forward is accompanied by a surge of fatal crashes and illness.

Although the chronic effects of staying on Daylight Saving Time have not been studied, it is understood to be less aligned with circadian biology. In August 2020, the American Academy of Sleep Medicine released two position papers recommending that seasonal changes be abolished in favor of year-round Standard Time. A group of international experts in chronobiology similarly called for abolishing Daylight Saving Time.

4 things to make transition back to Standard Time easier

Given that we’re stuck with switching back and forth for now, what can you do if you are one of those who feels put through the wringer by meddling with the clock?

  1. Don’t stay up late on the Saturday before the clocks change. We are already a sleep-deprived society and should take advantage of the extra hour of sleep coming on October 31.
  2. Don’t sleep in, and do give yourself as much light as possible when you wake up. You may not feel like throwing open the curtains as soon as you arise, but your body sets its rhythm in response to natural light, especially the short-wave light that predominates in the morning. It’s the signal that says, “Wake up!”
  3. Go easy on your caffeine and nicotine intake as you adjust.
  4. Set and stick to a regular sleep schedule.

When Daylight Saving was introduced a century ago, it seemed like a good thing because it meant less use of artificial light and more energy savings. But modern society, with its air conditioning, ubiquitous TV screens, and plethora of digital devices, uses plenty of energy whether the sun is shining or not.

Please send comments via the author's profile, where you can also ask Dr. Cytowic for copies of articles and papers, including “Your Brain on Screens.”


Malow, B.A., O.J. Veatch, and K. Bagai, Are Daylight Saving Time Changes Bad for the Brain? JAMA Neurology, 2020. 77: p. 9–10. doi: 10.1001/jamaneurol.2019.3780.

Daylight saving time: an American Academy of Sleep Medicine position statement. October 15, 2020.

Roenneberg T, et al. Why Should We Abolish Daylight Saving Time? J Biol Rhythms. 2019 Jun;34(3):227-230. doi: 10.1177/0748730419854197.

Manfredini, R., Fabbian, F., Cappadona, R., De Giorgi, A., Bravi, F., Carradori, T., ... & Manzoli, L. (2019). Daylight saving time and acute myocardial infarction: a meta-analysis. Journal of clinical medicine, 8(3), 404.

Roenneberg, T., Winnebeck, E. C., & Klerman, E. B. (2019). Daylight Saving Time-A Battle Between Biological and Social Time. Frontiers in physiology, 10, 944.

Zhang, H., Dahlén, T., Khan, A., Edgren, G., & Rzhetsky, A. (2020). Measurable health effects associated with the daylight saving time shift. PLOS Computational Biology, 16(6), e1007927.

For the earlier column on "5 Deadly Reasons Why Daylight Saving Time Is Bad for You," see…

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