Most of the country will turn back the clocks this weekend for the annual shift back to standard time.
The majority of people will do the switch before hitting the sack Saturday night, even though the change doesn't become official until 2 a.m. Sunday local time.
Residents of Hawaii, most of Arizona and some U.S. territories don't have to change since they do not observe daylight-saving time.
Public safety officials say this is also a good time to put a new battery in the smoke alarm, no matter where you live.
Daylight-saving time returns the second Sunday in March.