When Is Daylight Saving Time Ending: 'Fall Back' Happens While You Sleep

Daylight saving time ends while most people are asleep and the old saying "spring ahead, fall back," means setting the clock back one hour Sunday. That means more sleep for the weary but should the U.S. abolish daylight saving time?

The practice has been called into question recently and not all states recognize daylight saving time. In the U.S., time zones are controlled by the Department of Transportation, or DOT, and daylight saving time was first implemented as part of the Uniform Time Act of 1966. As the DOT explains, there were approximately 100 different local "sun times." The varying times caused confusion for travel, so the U.S. and Canadian rail systems established four time zones to replace local time.

The Interstate Commerce Commission oversaw time zones and boundaries as established by the Standard Time Act of 1918 until responsibility was transferred to DOT in 1966. The time zones established by the Standard Time Act, as amended by the Uniform Time Act, are Atlantic, eastern, central, mountain, Pacific, Hawaii-Aleutian, Samoa and Chamorro. While time zones were first established to ease confusion for railroads, the DOT lists three reasons for them to remain in place: energy savings, safety and crime reduction.

The idea that it saves energy has been called into question by several peer-reviewed studies, the Wall Street Journal reported. One study looked at the changes made in the Australian states of Victoria and New South Wales, which extended daylight saving time, and compared it to South Australia from 1999 to 2005. Energy use decreased in the evening -- supporting the argument made by the DOT -- but increased in the morning. Another study, conducted when Indiana adopted daylight saving time statewide, found an increase in energy usage.

Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and Arizona do not recognize daylight saving time and Utah is looking to abandon the practice. A number of states, including Indiana, have multiple time zones. Most recently, President Vladimir Putin abolished daylight saving time in Russia. Daylight saving time is practiced in most countries around the world including China, India, Iraq, Italy and Japan.

Most devices, including smartphones, tablets and cable boxes, will update automatically at 2 a.m., local time, Sunday. Watches and other manually programmed appliances will need to be adjusted.