Is it time to rethink the wisdom of Daylight Saving Time -- especially observing it for 7.8 months as we do now in the United States?
I think so.
The following 2008 study at University of California, Santa Barbara found:
"Our main finding is that — contrary to the policy's intent — DST increases residential electricity demand."
Back during World War II, when the main residential usage for electricity was lighting, there may have been a bit of an argument for DST.
Now that the use of electricity for heating and air conditioning outweighs that for lighting in the typical U.S. residence, DST has become more of a two-times-per-year annoyance, and is actually more likely "anti-green" (for those who care about such things).
Adding insult to injury, the typical home in 2009 is likely to have a few more timekeeping devices that need attention than did the typical home of the 1940s. E.g., PDA, answering machine, stove, microwave, vehicles, water softener.
NBER WORKING PAPER SERIES DOES DAYLIGHT SAVING TIME SAVE ENERGY? EVIDENCE FROM A NATURAL EXPERIMENT IN INDIANA