For nearly a century, Americans have been springing forward and falling back, and this year will be no different. Come Sunday morning, we'll all be snuggled soundly in bed when the clock changes an hour. Daylight saving time is the seasonal surprise that borrows an hour from our circadian rhythm in the spring and gives it back in the fall.

But whether or not we should disrupt the rhythm at all has spurred passionate debate from many disparate groups.

To better understand the situation, it's best to look at why we do these annual clock changes. Agrarian cultures built their societies around sunlight, waking up with the sun to toil in the field and heading home as the sun lowered beneath the horizon. But the industrial revolution brought with it the freedom to unshackle us from nature's clock.

As long ago as 1897, countries around the world began instituting daylight saving time, adding an hour of sunlight to the afternoon. This meant communities could be more productive — people could work longer, and when work was done it was still bright enough to run errands and stimulate the economy. The added daylight also meant more exposure to vitamin D and the added time for people to exercise outdoors.

Everyone from factory owners to retailers embraced the change. Even the candy lobby supported the new system, figuring the extra hour of sunlight meant it would be safer for kids to go trick-or-treating on Halloween.

"It has several technical benefits as well," Dr. David Prerau, author of "Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time," explained during a phone interview. "It's been found to reduce energy usage by doing something called load smoothing" — separating out electrical loads throughout the day to better deal with the valleys and peaks of energy usage — "and so you're going to generate energy more efficiently and therefore have less effects on pollution." A study by the U.S. Department of Transportation showed that the country's electricity usage is cut by 1 percent each day because of daylight saving time.

Some groups aren't fans of the time change

person watching tv at night in bedWhen it's darker earlier, people tend to stay home and watch more TV. That's why the TV networks don't like the time change in spring. (Photo: Vlue/Shutterstock)
But not everyone is on board with the time shift.

Michael Downing, a teacher at Tufts University and the author of "Spring Forward: The Annual Madness of Daylight Saving Time," says messing with the clock doesn't really save energy. "Daylight saving is still a boon to purveyors of barbecue grills, sports and recreation equipment and the petroleum industry, as gasoline consumption increases every time we increase the length of the daylight saving period," Downing tells MNN. "Give Americans an extra hour of after-dinner daylight, and they will go to the ballpark or the mall — but they won't walk there."

Daylight saving time increases gasoline consumption, according to Downing. "It is a convenient and cynical substitute for a real energy conservation policy."

There's data to back him up. A report by the California Energy Commission's Demand Analysis Office concluded that, "The extension of daylight saving time (DST) to March 2007 had little or no effect on energy consumption in California."

Television networks aren't fans of the time change either. The extra hour of daylight means fewer people are home to watch TV. Viewership ratings traditionally plunge each spring. In 2009, Fox's hit "American Idol" clocked in historic low ratings immediately following the spring time change. On average, primetime shows shed 10 percent of their viewers on the Monday after the clocks are changed.

"I think television networks would like it to be dark as soon as you left the office and headed home for the night," Bill Gorman, of the website TV by the Numbers, told NPR. "And maybe it started raining or snowing a lot as soon as primetime began."

And it doesn't look like those issues will end anytime soon. As part of the Energy Policy Act of 2005, Congress pushed daylight saving time three to four weeks deeper into the fall.

That change has resulted in sunrises as late as 8:30 a.m. in some areas, causing ripple effects in unexpected places. For example, it has thrown a wrench into the lifestyle of observant Jews whose morning synagogue services are predicated on the sun. In fact, Prerau points out, Israel has a relatively short daylight saving time compared to other countries. "If sunrise is late, religious Jews have to delay going to work or pray at work, neither of which is a desirable situation," he says.

If you're not a fan ...

Sun setting between saguaros cactus in Sonoran Desert, ArizonaPeople who live in Arizona (or Hawaii) never have to worry about springing forward or falling back. (Photo: Anton Foltin/Shutterstock)
"If you don't like daylight saving time, you have plenty of options," explains A.J. Jacobs, the best-selling author of "The Know-It-All." He suggests moving to Arizona or Hawaii, states that don't observe daylight saving time at all. "Parts of Indiana used to be DST-resistant as well, but I think they've since buckled."

Even for those who do live in such states, it's not all easy living. "It's crazy. People forget about us not changing so they call at ridiculous times," says Anita Atwell Seate, a doctoral student at the University of Arizona in Tucson. "But on the upside, you don't have to adjust your sleep schedule or your clocks."

Is daylight saving time a fait accompli or will time ever just stand still? Downing doesn't see a light at the end of the tunnel. "Since 1966, every 20 years, Congress has given us another month of daylight saving. We're up to eight months now," he says. "And there is every reason to believe that the [U.S.] Chamber of Commerce, the national lobby for convenience stores — which account for more than 80 percent of all gasoline sales in the country — and Congress will continue to press for extensions until we adopt year-round daylight saving. And then, why not spring forward in March or April and enjoy double daylight saving time?"