On March 10, clocks jump ahead an hour to welcome that harbinger of spring—daylight saving time (and it is daylight saving time, not savings time). Even though many people relish the extra hour of sunlight after work, the practice often wreaks havoc with sleep schedules and creates other health and safety issues. Here are a few facts about the leap forward:
- People often experience fatigue and even headaches during daylight saving time because sunlight suppresses the creation of melatonin, the body’s sleep-inducing chemical. For the 47 million Americans who already are sleep deprived, the effect of losing another hour of sleep can be considerable. “Losing an hour of sleep contributes to sleep debt,” Shyam Subramanian, a pulmonologist at Baylor College of Medicine and medical director of the sleep lab at Ben Taub General Hospital in Houston, told the Houston Chronicle in 2010. “If you don’t make up the debt, it manifests in waking up tired, needing a lot of caffeine to get going, nodding off during the day.”
- There’s an increase in occupational accidents during daylight saving time, especially among transportation workers and miners.
- Arizona and Hawaii are the only two U.S. states that don’t observe the time change at all.
- A 2008 Swedish study revealed a spike in reported heart attacks during the first week of daylight saving time. Some experts attribute the increase to a loss of sleep. “The most likely explanation to our findings are disturbed sleep and disruption of biological rhythms,” Imre Janszky, the lead author of the study, told National Geographic in 2011.
- Benjamin Franklin advocated daylight saving time in 1784 in France so Parisians would burn fewer candles. The United States adopted daylight saving time in 1918 at the end of World War I to conserve fuel.
- Fewer traffic accidents are reported during daylight saving time. Experts believe it’s because people drive more safely in the daylight.