Stop daylight saving time!
Stop daylight saving time!
This semiannual ritual shifts our rhythms and temporarily makes us groggy at times when we normally feel alert. Moreover, many Americans are confused about why we spring forward in March and fall back in November, and whether it is worth the trouble.
The practice of resetting clocks is not designed for farmers, whose plows follow the sun regardless of what time clocks say it is. And it does not create extra daylight – it simply shifts when the sun rises and sets relative to society's regular schedule and routines.
To this day, our laws equate daylight saving with energy conservation. However, recent research suggests that it actually increases energy use.
This is what I found in a study co-authored with Yale economist Matthew Kotchen. They used a policy change in Indiana to estimate daylight saving time's effects on electricity consumption. Prior to 2006, most Indiana counties did not observe it. By comparing households' electricity demand before and after daylight saving time was adopted, month by month, we showed that it had actually increased residential electricity demand in Indiana by 1 to 4 percent annually.
The largest effects occurred in the summer – when shifting clocks forward aligns our lives with the hottest part of the day, so that people tend to use more air conditioning – and late fall, when we wake up in a cold dark house and use more heating, with no reduction in lighting needs.
When we "spring forward" in March we lose an hour, which comes disproportionately from resting hours rather than wakeful time. Therefore, many problems associated with springing forward stem from sleep deprivation. With less rest, people make more mistakes, which appear to cause more traffic accidents and workplace injuries, lower workplace productivity due to cyberloafing and poorer stock market trading.
Even when we gain that hour back in the fall, we must readjust our routines over several days because the sun and our alarm clocks feel out of synchronization, much like jet lag. Some impacts are serious: During bookend weeks, children in higher latitudes go to school in the dark, which increases the risk of pedestrian casualties. Dark commutes are so problematic for pedestrians that New York City is repeating the "Dusk and Darkness" safety campaign that it launched in 2016. And heart attacks increase after the spring time shift – it is thought because of lack of sleep – but decrease to a lesser extent after the fall shift. Collectively, these bookend effects represent net costs and strong arguments against retaining daylight saving time.