for National Geographic News
This week the U.S. Congress is expected to pass a mammoth new energy bill that includes subsidies to oil and gas companies and encourages nuclear power. Yet the bill's most controversial aspect may be its monthlong extension of daylight saving time.
The move's energy-saving potential is uncertain. So few data exist on the subject that the plan calls for a new energy-impact study to be commissioned after the proposal becomes lawbut before clock changes would actually take effect in 2007.
The bill calls for daylight savings to begin three weeks earlier, on the second Sunday in March, and to end on the first Sunday in November, one week later than daylight saving time currently does (see the history of daylight saving time in the U.S.).
Advocates such as Massachusetts Democrat Ed Markey, who is co-sponsoring the bill in the House of Representatives, say the plan is about more than just saving energy.
"In addition to the benefits of energy saving, less crime, fewer traffic fatalities, more recreation time and increased economic activity, day light saving just brings a smile to everybody's faces," Congressman Markey said in a press statement.
Some of the bill's boosters cite U.S. Department of Transportation studies from the 1970s. The studies evaluated the 1974 and 1975 extensions of daylight saving time. The 1970s extensions were designed to address the energy crisis spurred by an oil embargo.
In 2001 then-acting deputy assistant secretary for transportation policy Linda Lawson discussed the 1970s research before the House Science Committee. She reported that the studies had found an extension of daylight savings in springtime "might result in electricity savings of 1 percent in March and April, equivalent to roughly a hundred thousand barrels of oil daily over the two months." (See "How Long Will Cheap Oil Last?")
The study also noted reductions in crime and traffic accidents, attributed to extended daylight hours.
But Lawson also cautioned the committee about drawing conclusions from studies that were already old in 2001.
"I want to note that these studies are over 25 years old and were limited in scope," she told the committee. "Congress captured many of the benefits identified in our studies in the legislative changes to daylight saving time enacted in 1986. There have been dramatic changes in lifestyle and commerce since we completed our studies that raise serious questions about extrapolating conclusions from our studies into today's world."
Energy-Savings Evidence in Short Supply
Recent research on the subject is thin on the ground. The state of California's energy commission, however, studied the effects of daylight saving time on energy costs during California's 2001 energy crisis.
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