Daylight Saving Time officially ends at 2 a.m. Sunday, giving most Americans an extra hour as clocks “fall back” to standard time—though for the vast majority, the switch will happen seamlessly on smartphones, computers, smart watches, and other connected devices.
Public safety officials are using the occasion to issue a critical reminder: replace the batteries in smoke and carbon monoxide detectors.
The clock change applies nationwide except in Hawaii, most of Arizona, and several U.S. territories. While digital clocks update on their own, some manual devices—car dashboards, microwaves, wall clocks, and certain medical equipment—may still require adjustment.
Sleep experts warn the one-hour change can still throw off circadian rhythms.
“Even with automatic clocks, your body doesn’t adjust instantly,” said Dr. Phyllis Zee, director of the Center for Circadian and Sleep Medicine at Northwestern University. “Get outside in natural light Sunday morning to help reset your internal clock.”
Debate over Daylight Saving Time continues, with growing public support for eliminating the biannual switch. For now, the ritual persists—complete with an extra hour this weekend.