daylight saving time Daylight saving time ends at 2 a.m. Sunday, Nov. 6.[/caption]

Daylight saving time ends early Sunday morning on Nov. 6, but what does that really mean?

According to the U.S. Department of Transportation, which regulates daylight saving time, the practice has three main benefits:

  • Energy conservation. The need to use electricity for household lighting is reduced because the sun sets one hour later in the evenings, and the later evening hours encourage outdoor activity. Sunrise is also earlier, meaning there is less indoor light usage in the early morning hours when people are getting ready for work.

  • Preventing traffic accidents. Additional daylight hours mean less night driving, and better visibility.

  • Crime reduction. Conducting business and personal errands during the day when it is light reduces the amount of time spent out at night, when more crime occurs.


States can choose whether to observe daylight saving time, but if it is observed, the state must abide by federally mandated dates.

Daylight saving time is not observed in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and most of Arizona, according to the U.S. DOT.

Daylight saving time will end this year at 2 a.m. Sunday, Nov. 6.

In 2017, it will begin at 2 a.m. on March 12 and will end at 2 a.m. Nov. 5.

Daylight saving time was first introduced in 1918 in the United States, according to National Institute of Standards and Technology, the county’s official timekeeper. A national standard was not developed until the Uniform Time Act of 1966 established a uniform daylight saving time for the U.S. and its possessions.

The rules for daylight saving time changed in 2007, extending its duration by about a month. It now begins the second Sunday in March and ends the first Sunday in November.

Daylight saving time is in effect for 238 days, or 65 percent of the year, according to NIST.