Extra hour of sun seems great, but daylight saving time really does harm your health | Opinion
The push for permanent DST could lock millions of people into a system where their clock setting remains artificially ahead of the natural solar time.
Every spring and fall, as we “spring forward” or “fall back,” many of us grumble about disrupted sleep and clock changes. But what if the twice-yearly rituals of setting our clock are only the tip of an iceberg – a sign of a deeper misalignment between our daily schedules and the natural rhythm of the sun?
Recent research makes a compelling case that the way we use our clocks and time zones isn’t just a means of standardization or a matter of convenience; it has serious implications for our mental health and overall well-being.
As we prepare for the clock change this year, on Sunday, it’s crucial to consider that the promise of longer evenings and extra daylight comes with a significant hidden health cost.
How does daylight saving time impact your sleep?
We live by the clock, yet our bodies follow the sun. Our internal rhythms – those cycles that control our sleep and wake times – depend on the natural pattern of daylight and darkness. Our bodies suffer when our daily schedules, dictated by clock time, stray too far from the natural cues provided by the sun.
This disruption, often called “circadian misalignment,” leads to sleep deprivation and increases the risk of depression and various adverse health outcomes.
Our recent study used data from the Centers for Disease Control and Prevention and modern statistical methods to determine how this misalignment, which is especially prominent for those living close to a time-zone border, affects our well-being, specifically mental health. People living just to the east of a time zone border experience later sunrises and sunsets compared with their neighbors immediately to the west.
This difference is not without costs.
Specifically, our study (forthcoming in the American Journal of Health Economics) has found that individuals who experience a substantial mismatch between clock time and solar time suffer a roughly 6% increase in the incidence of depression.
In other words, being out of sync with the sun can have measurable consequences on mental health.
Daylight saving time can affect your mental health
One important pathway is that this persistent mismatch disrupts our sleep patterns and leads to significant sleep deprivation. Daylight saving time exacerbates the circadian misalignment by shifting our schedules even further away from the natural sunlight cycle.
This issue goes far beyond a minor inconvenience. Around the world, 1 in 8 people suffer from mental health disorders, and in the United States, 23% of adults experienced significant mental health challenges in 2021.
These problems hurt individuals, reduce productivity and impose high costs on our health care systems and taxpayers.
The push for permanent DST could lock millions of people into a system where their clock setting remains artificially ahead of the natural solar time. In contrast, permanent standard time, which is more in tune with the Earth’s rotation and the sun’s cycle, would help preserve the natural balance that our bodies rely on.
As policymakers consider whether to eliminate the twice-yearly clock changes, they must recognize that our internal clocks are set by the sun. Ignoring this natural connection has serious consequences for our society’s well-being.
It is time for our policies – and our clocks – to catch up with our biology. Making daylight saving time permanent requires new legislation, but fortunately, making standard time permanent doesn’t.
States can follow Arizona’s and Hawaii’s lead – opting out of DST under the Uniform Time Act of 1966. With more policymakers recognizing the health and productivity benefits of aligning our clocks with the sun, a swift and smooth transition is well within reach.
Susan Averett is a professor of economics at Lafayette College in Easton, Pennsylvania. Laura Argys is a professor of economics at the University of Colorado-Denver. Muzhe Yang is a professor of economics at Lehigh University in Bethlehem, Pennsylvania.