Space & Innovation

Dangers of Daylight Savings Time

Having to reset your clock isn't the only drawback of this semiannual ritual.

| Corbis Images
| Corbis Images

The end of daylight savings time means that we all lose an hour of sleep this weekend.

Having to reset your clock isn't the only drawback of daylight savings. Explore some of the other dangers of daylight savings in this slideshow.

DNEWS VIDEO: Why We Have Daylight Savings Time

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An hour might not seem like a lot, but even that amount of time is enough to be disruptive to biological clocks. While falling back in the autumn can have little effect, springing forward throws off Circadian rhythms, which has implications for not just sleep but also immune function.

And according to a study published in 2007 in the journal BMC Biology, people never really adjust their Circadian rhythms to daylight savings even in the weeks that follow the time change.

Why Do We Have Daylight Savings Time?

A lab-grown heart could help the estimated 17 million people who die each year from heart disease. | Sciepro/Science Photo Library/Corbis

Lost sleep, disrupted circadian rhythm and a weakened immune system may seem like minor responses to the time change. Combine that with people suffering from heart conditions, and daylight savings, when spring forward, becomes a trigger for heart attacks.

According to a cardiovascular researcher at the University of Alabama, the Monday and Tuesday after the beginning of daylight savings is on average associated with a 10 percent increase in heart attack cases.

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Tired employees tend not to be productive employees, and adjusting their sleep patterns by changing times is bound to affect their performance.

A study conducted at Penn State's Smeal College of Business found that the time change "makes employees less likely to self-regulate their behavior and more inclined to spend time cyberloafing." Roughly 20 percent of the time assigned to perform a given task was used unproductively when study participants saw disruptions in their sleep patterns.

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Workplace injuries also increase as a result of the daylight savings time change, according to a study published in the Journal of Applied Psychology. Analyzing injury reports submitted to the Mine Safety and Health Administration over a 23-year period, researchers found that there were 3.6 more injuries on average on Mondays following the time change, with 2,649 more days of work lost as a result.

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When springing forward over the weekend, commuters lose an hour of sleep. Couple drowsy drivers with darker roads in the morning, and the result is an increase in traffic accidents on the Monday after the weekend. U.S. crash data show a 17 percent increase in accidents after springing forward.

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If your teenager doesn't get admitted into a top university this spring when college admissions letters start rolling in, don't hesitate to blame daylight savings.

Researchers found that students living in counties that observe daylight savings had SAT test scores that on average were 2 percent lower than those living in areas that didn't adjust their clocks, according to a study published in the Journal of Neuroscience, Psychology, and Economics.


Daylight savings is expensive. Factor in the heart attacks, the accidents, the lost productivity and more, and the total cost is $433,982,548 to the U.S. economy, or at least it was in 2010, according to an analysis by research firm Chmura Economics & Analytics.