It's a twice-yearly ritual for almost every American: moving the clocks ahead one hour onto daylight-saving time in the spring, then back again to standard time in the fall. But the big question is, "Why?"
"20/20" conducted an informal poll on a city street, and most of the people we spoke to thought daylight-saving time had something to do with agriculture.
One man said, "I think it started in the 19th century so the farmers would have more time to work on the fields."
A second passerby agreed, adding that "it gives them extra time to plant, extra time to harvest."
Is there any truth to that common belief? Several farmers were surprised to hear what the city folk had to say.
Pearce and Alice McKinney, sheep farmers in Indiana, said they don't use an alarm clock to wake up each morning. Getting up before dawn just comes naturally and no matter what the clock says, feeding time is feeding time for their animals.
According to Pearce McKinney, "This lifestyle dictates that you maintain them before you maintain yourselves. And with that in mind, clocks don't have a bearing on it."
In fact, many farmers don't like when the clocks change. Indiana recently became one of the last states to fully observe daylight-saving time after years of resistance by farmers who had lobbied against it.
"We did fight pretty hard not to have it," said Jim Benham, the president of the Indiana Farmers Union. "I know of no farm activities that benefit from having [daylight-saving time]."
Both Benham and Pearce McKinney agree on the reason for farmers' resistance. "You must understand, farmers don't like change," said McKinney.
So it's a myth that we follow daylight-saving time to help out the farmers. The real reason Congress decided to change the clocks is to save energy, but could that also be a myth?
It's an idea that dates all the way back to Benjamin Franklin.
Living in Paris in 1784, he wrote an essay jokingly suggesting that moving the hour of sunlight from the morning, when Parisians tend to be sleeping anyway, to the evening could save millions of candles.
"An immense sum that the city of Paris might save every year, by the economy of using sunshine instead of candles." Click here to read the entire essay.
The United States first adopted daylight-saving time in 1918 to save energy during World War I, then again for three years during World War II.
In the years following, there was no national policy, so states and counties were free to turn the clock back on their own. Confusion followed, leading Congress to finally pass the Uniform Time Act of 1966, which created daylight-saving time from the last Sunday in April through the last Sunday in October.
States could opt out if they liked, and several did -- including Arizona and Hawaii, which still don't follow daylight-saving time today.
During the Arab oil embargo in the 1970s, the United States temporarily extended daylight-saving time year-round.
The Department of Transportation was asked to study the results and released a report in 1975 that concluded that it was possible that 100,000 barrels of oil may have been saved by extending daylight-saving time by two months -- about 1 percent of the use at that time.
But the report also noted that "the potential benefits are small and difficult to isolate from the larger effects of seasonal variations and of changes in energy availability and prices."