Daylight Saving Time: It’s unclear why we do it or what good it does
Digital First Media
As we set our clocks forward an hour this Sunday, there are at least a few things we can be sure of:
* There will be lots of groaning about losing an hour of sleep,
* People will be cheery about the growing length of the day (and
* Lots of people will debate why we even have Daylight Saving Time.
The government tells us that DST does three fundamentally good things -- saves energy, saves lives by preventing traffic injuries, and reduces crime. But where’s the proof? Where are the studies?
"There’s really not anything recent that’s been done," said Bill Mosley, public affairs spokesman for the Department of Transportation, which oversees the nation’s time zones and observance of DST.
Mosley said that the reasons listed on the department’s website under the heading "Purpose of Daylight Saving Time" were "just general rationales given by Congress and other advocates."
"I think our staff (posted that) as general guidance," Mosley said. "We haven’t done any recent studies."
Few others appear to have researched it either ...
Does Daylight Saving Time really save energy?
Mosley did provide a 2008 study from the U.S. Department of Energy that examined energy savings, but it only measured how much energy was saved from the extension of DST that happened in 2007.
That extension pushed the spring forward time change up by about a month, from the first Sunday in April to the second Sunday in March, and pushed the fall back change from the last Sunday in October tothe first Sunday in November.
The study’s findings were pretty minor -- a total of 0.02 percent of the nation’s total energy consumption was saved.
There’s some evidence that the heating and cooling costs could be killing those savings, too.
According to the History Channel, economists determined that when Indiana moved to DST in 2006, electricity use increased 1 percent because there was more demand for air conditioning in the summer and heat in the cooler months.
OK, but preventing traffic injuries seems to make sense The Department of Transportation tells us that during DST, lives are saved and traffic injuries are prevented because "more people travel to and from school and work and complete errands during the daylight." That seems logical, but has it been proved?
"We have traffic safety data, but it’s not specifically linked to Daylight Saving Time," Mosley said. "There was something done decades ago, but nothing recent that would say what the impact of (DST) is on traffic."
A Forbes article from 2009 states that 49 percent of fatal crashes happen at night. Though more crashes happen during the day, the fatality rate per mile of travel is about three times greater at night, according to Forbes. Drunken driving, speeding and driving without a safety belt also increase at night.
Most pedestrian-car deaths occur at night, reports the Centers for Disease Control and Prevention, but again, it’s not as simple as saying that more people are hit by cars when it’s dark out. Alcohol, age and the speed of the driver are also big factors, as are where those types of accidents happen -- typically in urban areas, but not at intersections, reports the CDC.
What about people falling asleep at the wheel? Those crashes are more likely to happen "at night or during the midafternoon, when drivers are more likely to be sleepy," states a study by the National Highway Traffic Safety Administration. The data does not specify that darkness causes sleepiness, nor does it give a specific timeframe for those evening and midafternoon hours.
A 2010 study by NHTSA found that about 20 percent more people drive without seat belts at night, but does not delve deeper into how the time of day affects crash data.
Crime must decrease when it’s brighter out, right? Nope, or at least there doesn’t appear to be anything definitive backing that up.
Trulia, a real estate website, compiled a bunch of crime maps in 2011. It found that the times crimes are likely to occur vary quite a bit based on the city you live in, but some of its general findings actually run contrary to the idea that crime goes up when it’s dark out.
The dead of the night, 3 a.m., is a low-volume hour for crime, while most places see an uptick right around 9 a.m. -- when everyone has left their homes empty while they head to work.
Trulia did find that most violent crimes happen around 9 p.m., so that’s at least something to consider.
So who wants Daylight Saving Time anyway?
Candymakers, retailers and recreation advocates were among the lobbying groups who supported extending DST when Congress was debating the matter in 2005.
There’s evidence the candy industry provided at least minimal support to extending DST, as Halloween was included in the expansion.
A USA Today article from 2005 said retailers thought it would boost business by keeping people out shopping later. It also gave the rationale of a sporting goods association president that kids would play outside rather than watch TV.
Supporters within congress at the time cited a study from the 1970s that projected energy savings. Also noteworthy: A co-author of the bill called its passage "a huge victory for sunshine lovers."
Other things you should probably know about Daylight Saving Time
First off, most people get the name wrong. It’s Daylight Saving Time -- the middle word isn’t plural. A quick Google search trend shows the majority of people are searching for the incorrect term.
Second, there’s no correlation to farming. The History Channel tells us that farmers aren’t big fans of the time change. Why we have DST has more to do with railroads and wars.
Also, states can decide whether they want to participate in DST. Some don’t. Hawaii, most of Arizona and American Samoa, Guam, Puerto Rico and the Virgin Islands opt not to participate. Indiana wasn’t fully on board until 2005.
Convinced you don’t need it either? People are petitioning the WhiteHouse to get rid of DST all together. Only 7,247 people have signed the petition, so it’s pretty far from meeting the goal of 100,000 signatures by April 4, which should net the petition an official response.
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