There’s no proof daylight saving time saves electricity, so why do we even bother?

If you’re looking for someone to blame for daylight saving time, allow us to suggest the Germans.

After all it was Germany which, in April, 1916, first started moving clocks forward by an hour, to conserve energy during World War I. The rest of Europe followed, as did the US, in 1918. They dropped it after the war. But in WWII they adopted it again.

The US went to summer DST after the war. (It tried year-round DST at the peak of the oil embargo of 1970s.) Then sky-rocketing oil prices pushed the US to extend DST by four-weeks in the Energy Policy Act of 2005, which took effect in 2007.

The idea behind daylight saving time is to cut back on residential electricity use, which is heaviest at night. By moving the clocks forward in the spring, human activity would start and end earlier, and when people returned to their still-sunny houses after work, they wouldn’t need to turn on the lights until an hour later than normal. The result? Energy savings.

But there’s little empirical proof it actually works.

For instance, one 2007 study looked at two neighboring Australian states. Victoria extended daylight savings time as part of the national plan to facilitate the 2000 Olympic games. South Australia, next door, did not extend DST. The upshot? They found DST did reduce energy use in the evenings. But it also boosted energy usage in the mornings, essentially negating all the savings.

Another bit of research zeroed in on a natural experiment built around the US state of Indiana, which until 2006 had a patchwork approach to daylight saving time in which some counties participated and others didn’t. The researchers looked at electricity demand for counties that didn’t have daylight saving time for 30 years, and then started in 2006. The results?

We find that the overall DST effect on electricity consumption runs counter to conventional wisdom: DST results in a 1-percent overall increase in residential electricity demand, and the effect is highly statistically significant.

A paper published in 2014 in the Journal of Economic Behavior & Organization sheds some light on why this might be. The short version seems to be that daylight saving time seems to change people’s behavior. The authors of the paper looked at data from the American Time Use Survey, a giant, federally administered national study on how Americans spend their time. They looked at more than 88,000 survey responses between 2003 and 2011 of people who answer on a weekday one week before or after the DST went into effect. “We see that on average individuals sleep for 15–20 min less and spend most of that extra time awake and at home. This will encourage additional use of both lighting and heating energy during that–colder and darker–period,” they wrote of the DST shift in the Spring, when impacts were the most pronounced.

In other words, some of the energy conservation benefit of having more hours of daylight in the afternoon, could be eaten up by early morning electricity and heat use. The paper takes pains to point out that their paper doesn’t tell us conclusively that DST doesn’t save energy, it does illuminate why the expected benefits might not be showing up.

“Slowly people are realizing that the energy savings is not there,” says Alison Sexton, one of the co-authors on the 2014 paper, on the subject of what research suggests about DST. “So is there reason to go on?”

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