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.
