How switching the clocks can affect your health

Much of the world adjusts their clocks each spring and fall. In the fall, clocks are fixed on standard time, while in the spring they’re moved forward one hour to daylight saving time, or DST.

The rationale behind DST has long been based on energy savings, as the demand for electricity to light homes is related to the times when people go to bed at night and rise in the morning. Studies conducted by the U.S. Department of Transportation in 1975 determined that moving clocks ahead one hour could save a small amount of energy each day. In New Zealand, power companies registered a 3.5 percent decrease in usage when daylight savings starts. Even though the energy savings associated with DST can be significant, some suggest those savings come at the expense of human health.

Research suggests that a onehour time change twice a year can significantly throw off humans’ internal clocks. A report conducted by the Massachusetts Legislature in the summer of 2016 found that people lose a significant amount of sleep in the days following DST, which can lead to an increase in both traffic fatalities and on-the-job injuries. Disrupted sleep cycles can leave people restless and coping with anxiety. A 2012 study published in the Journal of Applied Psychology found shifts related to DST led to killing time on the internet and other “loafing” around from lack of energy and motivation.

Finnish researchers analyzed more than 10 years of stroke data and its relation to DST. The overall rate of ischemic stroke increased by 8 percent in the first two days after transitioning to DST.

Similarly, other issues arise when clocks are switched back to standard time in the fall. Danish researchers found the rate of people seeking care for depression rose for up to 10 weeks after clocks were turned back.

Various petitions have been created to urge legislators to maintain DST all year long. The United Kingdom-based Royal Society for the Prevention of Accidents says doing so will reduce road deaths currently caused by darker evenings in autumn and winter. Keeping the time consistent can help avoid body clock resets, may prevent accidents and could increase productivity in the evening hours when the autumn arrives. Only time will tell if turning the clocks back and moving them forward will become a relic of the past.