At 2 a.m. on Sunday, March 11 time leaps forward one hour as Daylight Saving time begins.
Benjamin Franklin came up with the idea of resetting clocks during the summer in order to save energy. The practice became widespread in 1918 as a way to reduce the number of hours homes needed to use lighting and electricity.
Daylight Saving became a federal law in 1966, but some states opted out of observing it.
Arizona, American Samoa, Hawaii, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands do not lose an hour during their days—except for protected lands of the Navajo Native American tribe in Arizona, who do observe the time change.