I managed to make it through the whole day yesterday without my usual twice-yearly rant about daylight saving time. The truth is that Kelly and I completely forgot about DST ending and woke up thinking it was later than it actually was. Other than resetting far too many clocks it was a smooth transition for us.
Likewise, Matthew Kotchen, an economist at the University of California, saw in Indiana a situation ripe for study.
Prior to 2006 only 15 of the state’s 92 counties observed daylight saving time. So when the whole state adopted daylight saving time, it became possible to compare before-and-after energy use. While use of artificial lights dropped, increased air-conditioning use more than offset any energy gains, according to the daylight saving time research Kotchen led for the National Bureau of Economic Research [PDF] in 2008.
That’s because the extra hour that daylight saving time adds in the evening is a hotter hour. “So if people get home an hour earlier in a warmer house, they turn on their air conditioning,” the University of Washington’s Wolff said.
In fact, Hoosier consumers paid more on their electric bills than before they made the annual switch to daylight saving time, the study found.
This was also interesting:
Till Roenneberg, a chronobiologist at Ludwig-Maximilians University in Munich, Germany, said his studies show that our circadian body clocks—set by light and darkness—never adjust to gaining an “extra” hour of sunlight to the end of the day during daylight saving time.
“The consequence of that is that the majority of the population has drastically decreased productivity, decreased quality of life, increasing susceptibility to illness, and is just plain tired,” Roenneberg said.
One reason so many people in the developed world are chronically overtired, he said, is that they suffer from “social jet lag.” In other words, their optimal circadian sleep periods are out of whack with their actual sleep schedules.
Shifting daylight from morning to evening only increases this lag, he said.
“Light doesn’t do the same things to the body in the morning and the evening. More light in the morning would advance the body clock, and that would be good. But more light in the evening would even further delay the body clock.”
Changing the clocks might even result in increased chances of heart attack:
A 2008 study in the New England Journal of Medicine concluded that, at least in Sweden, heart attack risks go up in the days just after the spring time change. “The most likely explanation to our findings are disturbed sleep and disruption of biological rhythms,” lead author Imre Janszky, of the Karolinska Institute’s Department of Public Health Sciences in Stockholm, told National Geographic News via email.
I’m going to stick with my assertion that employers who want to shift the work hours of their employees during the summertime should be free to do so. The clocks should stay on standard time, though. Forcing nationwide jet-lag on the populace is a big price to pay for the disputed energy savings.