tagged w/ Daylight Savings Time
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Latest News Updates Official Time Change 2010: Daylight Saving Time (DST) Ends Today! Daylight Saving Time, which commences in spring of each year and ends in the fall, actually ends today, November 7.Latest News Updates Official Time Change 2010: Daylight Saving Time (DST) Ends Today!... more
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It's that time of the year again when we have to adjust our clocks (the ones that don't automatically adjust themselves) from Daylight Savings Time 2010 back to standard time..It's that time of the year again when we have to adjust our clocks (the ones that... more
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Starting this month, roughly one quarter of the world’s population will lose sleep and gain sunlight as they set their clocks ahead for daylight saving. People may think that with the time shift, they are conserving electricity otherwise spent on lighting. But recent studies have cast doubt on the energy argument—some research has even found that it ultimately leads to greater power use.
Benjamin Franklin is credited with conceiving the idea of daylight saving in 1784 to conserve candles, but the U.S. did not institute it until World War I as a way to preserve resources for the war effort. The first comprehensive study of its effectiveness occurred during the oil crisis of the 1970s, when the U.S. Department of Transportation found that daylight saving trimmed national electricity usage by roughly 1 percent compared with standard time.
In 2006 Indiana instituted daylight saving statewide for the first time. (Before then, daylight time confusingly was in effect in just a handful of Indiana’s counties.) Examining electricity usage and billing since the statewide change, Kotchen and his colleague Laura Grant unexpectedly found that daylight time led to a 1 percent overall rise in residential electricity use, costing the state an extra $9 million. Although daylight time reduces demand for household lighting, the researchers suggest that it increased demand for cooling on summer evenings and heating in early spring and late fall mornings. They hope to publish their conclusions this year in the Quarterly Journal of Economics.
Investigators got another opportunity in 2007, when daylight time nationwide began three weeks earlier, on the second Sunday in March, and ended one week later in the fall. California Energy Commission resource economist Adrienne Kandel and her colleagues discovered that extending daylight time had little to no effect on energy use in the state. The observed drop in energy use of 0.2 percent fell within the statistical margin of error of 1.5 percent.
Not all recent analyses suggest that daylight saving is counterproductive. Instead of studying the impact daylight saving changes had on just one state, senior analyst Jeff Dowd and his colleagues at the U.S. Department of Energy investigated what effect it might have on national energy consumption, looking at 67 electric utilities across the country.
In their October 2008 report to Congress, they conclude that the four-week extension of daylight time saved about 0.5 percent of the nation’s electricity per day, or 1.3 trillion watt-hours in total. That amount could power 100,000 households for a year. The study did not just look at residential electricity use but commercial use as well, Dowd says.
[Cont'd at link]Starting this month, roughly one quarter of the world’s population will lose... more
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Turning your clock back on Sunday may be good for your heart.
Swedish researchers looked at 20 years of records and discovered that the number of heart attacks dipped on the Monday after clocks were set back an hour, possibly because people got an extra hour of sleep.
But moving clocks forward in the spring appeared to have the opposite effect. There were more heart attacks during the week after the start of daylight saving time, particularly on the first three days of the week.
"Sleep -- through a variety of mechanisms -- affects our cardiovascular health," said Dr. Lori Mosca, director of preventive cardiology at New York-Presbyterian Hospital, who was not involved in the research. The findings show that "sleep not only impacts how we feel, but it may also affect whether we develop heart disease or not."
The study was described in a letter published in Thursday's New England Journal of Medicine by Dr. Imre Janszky of the Karolinska Institute and Dr. Rickard Ljung of Sweden's National Board of Health and Welfare.
Janszky said he came up with the idea for the study after last spring's time change, when he was having problems adjusting.
"I was on the bus, quite sleepy, and I thought of this," said Janszky, who has done other research on sleep and health.
They took advantage of Sweden's comprehensive registry of heart attacks to see if the disruptions to sleep and the body's internal clock caused by a time change had any effect on heart attacks from 1987 to 2006. They compared the number of heart attacks on each of the seven days after the time shift with the corresponding day two weeks earlier and two weeks later.
Overall, in the week after "spring forward," there was a 5 percent increase in heart attacks, with a 6 percent bump on Monday and Wednesday and a 10 percent increase on Tuesday. In the week after "fall back," the number of heart attacks was about the same, except on Monday, which had a 5 percent decrease.
"The finding that the possibility of additional sleep seems to be protective on the first workday after the autumn shift is intriguing," the authors wrote.
Doctors have long known that Monday in general is the worst day for heart attacks, and they usually blame the stress of a new work week and increased activity. The Swedish researchers said their findings suggest that the minor loss of sleep that occurs at the end of ordinary weekends -- with people going to bed later on Sunday and getting up early on Monday -- might also be a contributing factor.
Last year, a study by American researchers found there were more pedestrian deaths during the evening rush hour in November than October as drivers and pedestrians adjust to the earlier darkness. They said the risk for pedestrians drops in the spring when clocks are set back and daylight comes earlier.
Sleep can affect the heart through changes in blood pressure, inflammation, blood clotting, blood sugar, cholesterol and blood vessels, Mosca said. She suggested that anxiety from changes in routine may also be a factor, in addition to loss of sleep.
Dr. Ronald Chervin, director of the University of Michigan's Sleep Disorders Center, said this is a "sleep-deprived society," and he advises taking advantage of Sunday's time change and getting an extra hour of sleep.
In the spring, he suggests gradually adjusting to the one-hour loss by going to bed and getting up 15 minutes earlier for a few days before the time change.
"We spend a third of our lives sleeping and people forget how much effect it has on overall health," he said
Turning your clock back on Sunday may be good for your heart.
Swedish researchers... more
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Just a friendly reminder peeps.
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