Daniel Lemire's blog

, 2 min read

Current Daylight saving time policies are insane

Daylight saving time (DST) is this insane practice whereas twice a year, clocks are moved forward or backward by an hour. It is still widespread throughout North America and Europe. As a kid, I was told that this was meant to help farmers. But farmers have traditionally opposed daylight saving time (though they no longer do). The real argument is that daylight saving time saves energy. Does it really save energy? This is disputed somewhat:

We estimate a cost to Indiana households of $9 million per year in increased electricity bills. We also estimate social costs of increased pollution emissions between $1.7 to $5.5 million per year. (Kotchen and Grant, 2011)

What is not disputed is that the change to daylight saving time increases significantly heart attacks:

Overall, we found an elevated incidence ratio of 1.039 (95% confidence interval, 1.003–1.075) for the first week after the spring clock shift forward. The higher risk tended to be more pronounced among individuals taking cardiac medications and having low cholesterol and triglycerides. (Janszky et al. 2012)

But if daylight saving time part of the year saves energy, wouldn’t year-long daylights saving time saves even more? Many people think so (e.g., see Ahuja and SenGupta, 2012). The objections to a permanent switch to daylight saving time comes from parents who fear that dark morning might increase accidents involving kids. Yet the evidence that daylight saving time is bad for students does not stand. Thus, Calandrillo and Buehler conclude that it is time to switch year-round daylight saving time:

(…) year-round daylight saving time would save hundreds of lives annually by decreasing motor vehicle and pedestrian fatalities. Furthermore, extra light in the evening hours reduces criminal activity and results in energy savings from decreased peak electricity demand. Finally, year-round daylight saving time would eliminate the negative effects caused by the current spring and fall time changes. (…)

I see no evidence in favor of the current system. It is insane.

If you are American, please sign the petition to stop this insanity.