Reminder: Time to Fall Back an Hour It's time to fall back. Most Americans will be able to get an extra hour of sleep this weekend thanks to the annual shift back to standard time. The change officially occurs at 2 a.m. Sunday, but most people will set their clocks back before heading to bed Saturday night. 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 at 2 a.m. local time March 9.