Different times, places do Daylight Saving Time differently
Posted March 7
Updated March 15
Don't forget to set your clocks forward an hour as Daylight Saving Time (DST) begins at 2 a.m. on Sunday. Before you schedule a meeting with colleagues around the world in the next few weeks, be sure to check if they've switched to their country's version of daylight saving.
DST is observed everywhere in the U.S. and its territories except Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and most of Arizona (except the territory governed by the Navajo Nation which does observe DST). Around the world DST is observed by about 70 of the world’s 196 countries including members of the European Union.
Rules on when to “spring forward” or “fall back” are not consistent either. Depending on the country, daylight saving may begin the first, second or last Sunday in March at either 2 a.m. local time or 1 a.m. UTC. Rules aren't consistent year to year either. For example: Brazil delays the start of DST when it falls over Carnival week and Morocco makes adjustments when Ramadan falls during the changes.
I won't soon forget the chaos that was caused when Congress amended the law in 2007 to begin saving daylight three weeks earlier and to stop a week later. While most computer operating systems did a pretty good job of patching the problem, not all software did. For some, the problems created lived up to the Y2K hype, and we got to relive it all over again in late October that year.
Confused? Me too. Perhaps some history will help.
Benjamin Franklin is generally credited with the idea of Daylight Saving Time in his essay titled “An Economical Project for Diminishing the Cost of Light” published anonymously in 1784 during a stay in Paris. However, Franklin’s essay focused not on adjusting our clocks but instead on making better use of morning sunlight. He wrote of his discovery that the sun rises as early as 6 a.m. leading him to the conclusion. Franklin could be a pretty witty guy.
As early as 1895, New Zealand entomologist George Vernon Hudson proposed a not one but two hour shift in October and March in a paper to the Wellington Philosophical Society. Hudson was interested in maximizing time available to collect insects.
In 1905, William Willett proposed moving clocks forward not 60 but 80 minutes. Further complicating things, his concept included changing clocks not twice as we do today but eight times, adding or subtracting 20 minutes each Sunday at 2 a.m. in April and September. Willett tirelessly promoted the idea but did not see his British Summer Time become a reality before his death. Willett is remembered in the “Daylight Inn” pub near his home in Petts Wood. A memorial marker also features a sundial permanently set to summer time. It reads “Horas Non Numero Nisi Æstivas" or "I only count the summer hours."
DST was implemented in the United States in 1918 as a wartime effort to save energy. Since then some studies say it decreases energy demands. Others say it increases it. Most studies agree on one thing: DST’s impact on residential electricity usage is only about 1 percent, or about $4 per household. A Tufts University study put the increase in energy demands during DST as high as 4 percent.
While there is logic to additional daylight hours during the drive home improving road safety, studies show a jump in accidents the Monday after we lose that hour of sleep. Traffic safety isn’t the only health concern opponents of DST cite.
A University of Alabama at Birmingham study reported a 10 percent increase in risk of having a heart attack the Monday and Tuesday after that lost hour in March. Interestingly, that risk falls an equal amount when gaining that hour back in October. A Swedish study by Imre Janszky published in the New England Journal of Medicine in 2008 found a similar pattern. DST proponents argue that extra evening daylight encourages more heart-healthy activity outside.
So what’s the solution? Time standards aren’t something for the grassroots level. Unfortunately we must look to political leaders to help sort this mess out. The federal government has been pretty quiet on the mater since adjusting dates in the Energy Policy Act of 2005, but state legislators around the country are coming up with their own solutions.
Bills have been introduced this year in Utah, Idaho, Kentucky, Florida and Tennessee. Best title award has to go to Florida’s "Sunshine Protection Act.” Similar bills have been introduced over the years in Alaska, Colorado and Nevada. Voters in a Michigan referendum briefly exempted the state from DST observance, but in another intuitive approved DST observation. Here in North Carolina, legislators have not followed their colleagues in other states. A look at the record shows no bills introduced since 1989 in the North Carolina General Assembly concerning Daylight Saving Time.
So what can we do? Set your clocks forward Saturday night, go to bed a little earlier each night this weekend (this was selected as National Sleep Awareness Week for a reason), and watch out for tired drivers next week. Or you can do what astronauts aboard the International Space Station do and use Greenwich Mean Time which is conveniently about halfway between ground control in Moscow and Houston. There are no time zones in space and daylight changes every 45 minutes so there isn't much point in saving it.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.