Loved by some, loathed by many, our biannual clock twirling ritual has wide-ranging and often surprising implications.
From energy use to our very health, here's a look at some of the mythology and facts surrounding DST.
One of the most commonly offered rationales for daylight saving time (yes, it's "saving," not "savings") is the presumption that by extending summer daylight later into the evening, Americans would use less energy.
It was the reason Congress used in enacting daylight saving time during World War I and again after the United States joined WWII, according to author David Prerau.
Unfortunately, it doesn't seem to hold true.
A 2008 U.S. Department of Energy study
reported that daylight saving time reduces annual energy use by about 0.03%. And a study
that same year from the University of California-Santa Barbara found it might even increase energy consumption.
After Indiana adopted daylight saving time statewide in 2006, researchers examined power usage statistics and found that electricity consumption there rose 1% overall, with a 2% to 4% increase in the fall months.
The additional power usage cost Indiana power users $9 million a year and increased pollution, to boot, the researchers found.
Springing forward and falling back can be rough on our health
A 2012 British study
found kids got more exercise during the longer summer day. That's good. Then again, researchers at the University of Alabama Birmingham reported in 2012
that the spring adjustment led to a 10% increase in heart attack risk.
On the other hand, that same study found the risk fell about as much in the fall, when clocks were turned back.
The clock changes can also raise the risk of accidents by sleep-deprived motorists. The New England Journal of Medicine published a study in 1996 reporting an 8% increase in traffic accidents
on the Monday following the spring shift.
The good news is that the extra sleep makes streets about 8% safer on the day after the fall change, according to that study.
But hey, you're less likely to get robbed!
"When DST begins in the spring, robbery rates for the entire day fall an average of 7 percent, with a much larger 27 percent drop during the evening hour that gained some extra sunlight," the Brookings Institution reported in 2015
, citing research from the think tank's then-upcoming paper in the The Review of Economics and Statistics.
Let's leave the farmers out of this, okay?
The idea that daylight saving time was created to help farmers get their harvests in is so ingrained into the national consciousness, it's hard to believe it's not true.
But it's not, according to Prerau, whose 2009 book "Seize the Daylight" traces the history of the time shift.
Farmers, in fact, vociferously fought the proposals, arguing they cut productivity and made life overall tougher for them.
"If you want to cut off 25 per cent of the productiveness of the American farmer, just keep this law on the books," Prerau quotes one agricultural lobby as arguing during an effort to repeal daylight saving time in 1919.
Fewer and fewer of us think it's worth the trouble
A 2014 Rasmussen poll
found that a declining percentage of adults in the United States -- 33% -- think daylight saving time is "worth the hassle." That's down from 37% in 2013 and 45% the year before.
Efforts to kill off daylight saving time are nearly as old as the time shift itself, and even today, some are trying to get it repealed.
More than 63,000 people have signed a petition sponsored by the DST-hating website standardtime.com
. A search on Change.org returns 1,466 petitions mentioning daylight saving time, most of which appear to support abolishing it.
Others like it so much they want it to be kept year round (standard time, by the way, is standard in name only ... We go seven months of the year now with the extra hour tacked on at the end of the day).
Brookings, for instance, seems to be on board with the year-round DST approach, saying the costs and dangers are associated less with the shift forward than the constant back and forth.
"We could easily avoid them by moving to year-round DST -- that is, permanently shifting that hour of daylight to the evening, and then leaving our clocks alone," Jennifer L. Doleac and Nicholas J. Sanders wrote in the Brookings piece. "Our research suggests that we'd be safer for it."