Grab an extra cup of coffee tomorrow morning. At 2:00 a.m. local time on Sunday, most of the United States will officially “spring forward,” marking the start of Daylight Saving Time (DST).
While the change technically occurs in the middle of the night, most residents are advised to set manual clocks ahead one hour before heading to bed tonight. Digital devices, including smartphones, computers, and smartwatches, are programmed to update automatically.
The shift means the sun will rise and set one hour later than it did today. While the “lost hour” of sleep often leads to a groggy Sunday morning, proponents of the system highlight the benefit of extended evening light as we approach the spring equinox on March 20.
In most major cities, the sun will now set after 7:00 p.m. for the first time since last autumn.
Fire departments across the country traditionally use this weekend to remind residents to change the batteries in their smoke and carbon monoxide detectors.
Health experts warn that the one-hour disruption can temporarily affect circadian rhythms. Studies have shown a slight uptick in traffic accidents and heart attacks in the Monday immediately following the “spring forward” shift due to sleep deprivation.
Not everyone will be adjusting their watches tonight. Hawaii and most of Arizona (with the exception of the Navajo Nation) observe Standard Time year-round and will not change their clocks. Several U.S. territories, including Puerto Rico, Guam, and the U.S. Virgin Islands, also do not participate in the biannual ritual.
19 states have passed legislation or resolutions to move to permanent Daylight Saving Time, but any such change requires an act of Congress. Despite various bills introduced in recent years—including the “Sunshine Protection Act”—federal law currently only allows states to opt out of DST (staying on Standard Time), not to adopt DST permanently.
For now, the 23-hour day is here to stay. Standard Time is scheduled to return on November 1, 2026, when we will once again “fall back.”