WASHINGTON Energy-guzzling Americans, always on the lookout for a painless path to conservation, can celebrate this weekend when they will cut greenhouse gas emissions by simply pushing forward the hands on their clocks.
At 2 a.m. Sunday (0700 GMT), the United States will "spring forward" one hour to daylight saving time, three weeks earlier than usual, and will stay on that schedule until November 4, a week longer.
The additional four weeks each year of shifting an hour of daylight from morning to evening is expected to cut fuel consumption, as demand falls for electricity during early evening peak hours, according to experts.
For a country deeply divided on most issues, it should come as no surprise the expanded daylight saving time has plenty of advocates, besides environmentalists, and lots of detractors.
Softball teams, which gather on playing fields after work, will be able to start their seasons earlier, as will backyard barbecue enthusiasts. Candy manufacturers see brisker sales at Halloween as children will have an extra hour of daylight to go door-to-door begging for sweets during the late-October holiday.
Some in law enforcement think evening crime rates could fall.
But if you're an early riser or in the transportation industry, the idea stinks.
Farmers will lose a precious hour of early light. Orthodox Jews, who wait until sunrise to say morning prayers, lobbied against the provision, and airliners complained it would throw their international schedules further out of sync with Europe, costing the industry millions of dollars.
Owners of BlackBerrys and other electronic gizmos have had to scurry to download "patches" to make sure their devices are aligned with the new time three weeks earlier than programmed.
For U.S. companies, the time shift is nothing like the "Y2K" problem of eight years ago, when billions of dollars and countless man-hours were spent in an effort to protect computer systems as their clocks ticked over to 2000 from 1999.
"It is going to be a nuisance, not a disaster," said John Pironti, a risk strategist at Dutch computer services company Getronics.
Rep. Ed Markey, the Massachusetts Democrat who pushed to expand daylight saving time as part of a broader measure passed by Congress in 2005 encouraging new energy technologies, sees nothing but sunshine in the idea.
The energy savings would translate into a 10.8 million-metric-ton reduction in carbon emissions over the next 13 years, Markey said, citing an analysis by the American Council for an Energy-Efficient Economy.
Scientists link carbon dioxide, released when coal, oil and natural gas are burned, to global warming and environmental hazards.
While 10.8 million metric tons of carbon emissions may sound like a lot, it pales in comparison to the 5.9 billion metric tons the United States emitted just in 2004, according to the U.S. Department of Energy.
(Additional reporting by Franklin Paul in New York)