Daylight Savings Time: Set Your Clocks Back 1 Hour on Nov. 4th

On Sunday, November 4, 2012, most of the US, Canada and Mexico's  cities will end daylight saving time (DST) at 2am (02:00) local time.


How and When Did Daylight Saving Time Start?

While serving as U.S. ambassador to France in Paris, Franklin wrote of being awakened at 6 a.m. and realizing, to his surprise, that the sun would rise far earlier than he usually did. Imagine the resources that might be saved if he and others rose before noon and burned less midnight oil, Franklin, tongue half in cheek, wrote to a newspaper.
"Franklin seriously realized it would be beneficial to make better use of daylight but he didn't really know how to implement it," Prerau said.
It wasn't until World War I that daylight savings were realized on a grand scale. Germany was the first state to adopt the time changes, to reduce artificial lighting and thereby save coal for the war effort. Friends and foes soon followed suit.
In the U.S. a federal law standardized the yearly start and end of daylight saving time in 1918—for the states that chose to observe it.
During World War II the U.S. made daylight saving time mandatory for the whole country, as a way to save wartime resources. Between February 9, 1942, and September 30, 1945, the government took it a step further. During this period daylight saving time was observed year-round, essentially making it the new standard time, if only for a few years.
Since the end of World War II, though, daylight saving time has always been optional for U.S. states. But its beginning and end have shifted—and occasionally disappeared.
During the 1973-74 Arab oil embargo, the U.S. once again extended daylight saving time through the winter, resulting in a one percent decrease in the country's electrical load, according to federal studies cited by Prerau.
Thirty years later the Energy Policy Act of 2005 was enacted, mandating a controversial monthlong extension of daylight saving time, starting in 2007.