At 2 a.m. on Sunday, Nov. 4, most U.S. residents will be moving their clocks back an hour to mark the end of Daylight Saving Time.
Not all states, however, will observe the time change. Residents of Arizona, Hawaii and U.S. territories like Puerto Rico, Guam and the Virgin Islands will remain on their normal schedules.
In the U.S., the upcoming time shift is part of a longstanding tradition in which most residents set their clocks ahead an hour in the spring ("spring forward") and turn them back an hour as winter approaches ("fall back").
The idea behind Daylight Saving Time is to use the "extended daylight hours during the warmest part of the year to best advantage."
The time shift is said to reduce the need for lighting during the evening, which is why the changeover is considered an energy-saver.
However, experts are divided as to whether or not this true.
According to National Geographic, several studies conducted in recent years have suggested that Daylight Saving Time "doesn't actually save energy and may even result in a net loss."
Where did all this start?
Benjamin Franklin has been credited with the idea of Daylight Saving Time, but Britain and Germany began using the concept in World War I to conserve energy, the Washington Post observes. The U.S. used Daylight Saving Time for a brief time during the war, but it didn't become widely accepted in the States until after World War II.
In 1966, the Uniform Time Act outlined that clocks should be set forward on the last Sunday in April and set back the last Sunday in October. That law was amended in 1986 to start Daylight Saving Time on the first Sunday in April, but the new system wasn't implemented until 1987.
The end date was not changed, however, and remained the last Sunday in October until 2006.
Nowadays, Daylight Saving Time begins on the second Sunday in March and ends on the first Sunday in November.
One of the arguments to wait even longer to change the clocks back has to do with Election Day.
When the voters go to vote this year, the clocks have already been turned back, making it darker in the afternoon and lighter in the early morning hours.
Would that extra hour of daylight in the afternoon that's about to disappear be beneficial for getting more voters out to vote?
Some think it might.