When Daylight Saving Time 2017 Is and Why We Do It

Daylight saving time (DST) ends on Sunday, Nov. 5, 2017 at 2 a.m. ET. Most Americans will set their clocks back an hour at this time. This makes for darker days, but they will gain an extra hour of sleep.

The tradition of daylight saving time can be traced back to 1908 and is thought to have been originally conceived by founding father Benjamin Franklin.

However, it is New Zealand scientist George Vernon Hudson who is first credited for proposing a two-hour shift forward in the fall and a two-hour shift back in the spring. And in 1905, British builder William Willett set his clocks ahead and publicly campaigned about the “waste of daylight” in 1907. In 1916, Germany became the first country to enact daylight saving time in order to “save fuel” and conserve electricity during World War I. The United Kingdom followed weeks after.

The United States adapted DST in 1918, when President Woodrow Wilson signed it into law. Many Americans believe the practice of setting clocks forward by an hour during the summer, and back an hour in the fall, was put in place to help farmers. But it was actually pushed into solidification by department stores, who cited positive sales results with an extra hour of light.

Many also believe that DST helps conserve energy, but a study debunked this theory in 2008, showing that DST actually increases demand for more energy.

DST is deemed useless by its many critics, who cite its downsides as a loss of productivity, causing seasonal depression disorder in people, and negatively impacting the environment.

But most of the United States continue to observe DST—with the exception of Hawaii, overseas U.S. territories and Arizona (although, the Navajo Indian Reservation, whose territory lies in Arizona, still does).