The move to turn the clocks forward by an hour on March 11 rather than the usual early April date was mandated by the U.S. government as an energy-saving effort. But other than forcing millions of drowsy American workers and school children into the dark, wintry weather three weeks early, the move appears to have had little impact on power usage. Households drew less electricity for lights at night, but used more power early in the day as they woke to darker and chillier mornings.