FORT COLLINS, Colo. -- It not only costs most people an hour of sleep, now officials and researchers are questioning the value of daylight saving time.

Daylight saving time starts on Sunday at 2 a.m. Remember to set your clocks one hour ahead tonight.

The concept was first put forward by Benjamin Franklin, as a satire, during a visit to Paris. He wrote that fewer candles would be used if people got up earlier and went to bed earlier.

The city's engineer for energy services says moving the clock forward, even starting the shift earlier, seems to merely shift energy use to different times.

"At the end, all I could say was that we were shifting it around," John Phelan told The Coloradoan. Studies were "very inconclusive."

A study by the University of California-Santa Barbara, found that daylight saving increases energy use. It was based on a study of households in Indiana. An earlier study of energy in Australia came to similar conclusions.

Until last year, the U.S. had "sprung forward" on the first Sunday in April since 1966, with exceptions for the energy crisis in 1974 and 1975. Now most of the country will shift to daylight saving Saturday night. Standard time returns Nov. 2.

Opponents of the change have ranged from people worried that children will be going to school in the dark to drive-in movie theaters, most of which have gone out of business in recent years.

Some Colorado teachers fear performance on CSAP tests, which begin Monday, will be adversely affected.

Dr. Ron Kramer, director of Colorado Sleep Disorders Center, told The Camera that most people recover within a couple days. "For the most part, it's like taking an airplane ride to Chicago," Kramer said.