U.S. clocks will "spring forward" again on March 13 to make room for an extra hour of sunlight in the evenings as winter fades away.
Daylight saving time officially starts at 2 a.m. Sunday when clocks are turned forward one hour to 3 a.m.
Here are five things to know about daylight saving time before you adjust your watches, alarms and microwaves (most cell phones adjust on their own):
How It Affects Your Health:
The hour of sleep lost – or gained – may play a bigger, perhaps more dangerous role in our body’s natural rhythm than we think.
According to a University of Colorado study, researchers found a 25 percent jump in the number of heart attacks occurring the Monday after we “spring forward” compared to other Mondays during the year – a trend that remained even after accounting for seasonal variations in these events.
"[Heart attacks] were much more frequent the Monday after the spring time change and then tapered off over the other days of the week," lead author Dr. Amneet Sandhu, a cardiology fellow at the University of Colorado in Denver, said in an American College of Cardiology news release. It may mean that people who are already vulnerable to heart disease may be at greater risk right after sudden time changes."
When Was DST Implemented
Before President Lyndon B. Johnson signed the Uniform Time Act in 1966, which established a uniform daylight saving time, local governments could start and end daylight saving time as they desired. For five weeks a year Boston, New York and Philadelphia were not on the same time as Washington, D.C., Cleveland or Baltimore. Different daylight saving times also caused confusion for travelers going from the Midwest to Northeast.
In 2005, President George W. Bush extended the daylight saving time for an extra four weeks through an energy bill. Since 2007, daylight saving time has begun on the second Sunday of March, ending on the first Sunday of November.
Not All States Observe DST
Arizona and Hawaii are the only two states that do not observe daylight saving time. Indiana did not observe the practice until 2005. The American territories of American Samoa, Guam, Puerto Rico and the Virgin Islands also do not participate.
Some states have tried to get rid of daylight saving time but haven't been successful. In the last year alone, 14 state legislatures have debated bills aimed at revising how we keep time. In March, the Utah state legislature rejected a bill that would have ended daylight saving time.
Founding Father Did Not Come Up with DST
According to the History Channel, Benjamin Franklin did not come up with the idea of daylight saving time; he only suggested a change in sleep schedules.
Englishman William Willett is the one who suggested in 1905 that the United Kingdom move its clocks forward by 80 minutes between April and October, so people could enjoy the sunlight. He published "The Waste of Daylight" and spent much of his fortune and time promoting the idea.
DST is Singular Not Plural
By the way, it's "daylight saving time," not "daylight savings time."