Q. Is there a scientific reason that adopting year-round daylight saving time would not be feasible?
A. There is no reason that any time plan cannot be adopted by human beings, but whether year-round daylight saving time would achieve its chief goal -- saving energy -- is another question.
A later sunset time leaves a shorter time between darkness and bedtime for use of lights and appliances.
In many places, such energy saving does occur. A study done by the State of California in 2001 found small but significant energy savings in both winter and summer with a later sunset.
Another study, however, published in 2008 after Indiana switched the whole state to daylight time, concluded, "Our main finding is that -- contrary to the policy's intent -- D.S.T. increases residential electricity demand." While lighting use decreased, use of energy for heating and cooling increased. After a 2008 report by Department of Energy officials, some researchers said that even though extending daylight time had helped save energy nationally, regional variations made it impossible to predict whether year-round daylight time would do so. Because of air-conditioning use, for example, the South showed smaller savings.
The study also listed potential nonenergy problems with extended daylight time, including children's having to travel to school in darkness and higher traffic accident and crime rates.
C. CLAIBORNE RAY
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This article originally appeared in The New York Times.