Daylight saving time ended at 2:00 a.m. on Sunday, November 1, 2026. Most atomic clocks quietly fell back an hour on their own, which is exactly why people buy them. But if yours is still showing summer time, or it is suddenly an hour (or three) off, don’t worry. The cause is almost always a setting or a reception problem, and both are easy to fix.
How your atomic clock knows the time
A home “atomic” clock doesn’t have an atomic clock inside it. It has a small radio receiver that listens for WWVB, the 60 kHz time signal broadcast by the National Institute of Standards and Technology (NIST) from its station near Fort Collins, Colorado. That signal carries the official U.S. time, the date, and a flag that announces when daylight saving time starts and ends.
Most clocks listen overnight, when the signal travels farthest, and correct themselves automatically. Between updates they keep time like any ordinary quartz clock. (Curious about the source of the signal? Read The Atomic Clock in Colorado: A Journey Through Time.)
Why it didn’t change: the usual suspects
- The DST setting is turned off. Many clocks have a DST ON/OFF option. If it is off, the clock ignores the time change. It should only be off in places that don’t observe daylight saving time, such as Hawaii and most of Arizona.
- The time zone is wrong. WWVB broadcasts Coordinated Universal Time, and your clock converts it using the time zone you picked. A clock set to Eastern time in Chicago will be exactly one hour off, which looks just like a daylight saving problem.
- It hasn’t caught the signal yet. If the clock couldn’t hear WWVB overnight, it simply doesn’t know the time changed.
- The batteries are weak. Low batteries are one of the most common reasons a clock stops picking up the signal, even while the display still looks fine.
How to fix it in four steps
- Check the time zone and DST settings. Most clocks use a SET or TIME ZONE button; on many models you hold it for a few seconds to enter setup. Choose your time zone and make sure DST is ON (unless you live in Hawaii or most of Arizona). Your manual will show the exact buttons.
- Put in fresh batteries. Then press the reset button if your clock has one, or leave the batteries out for about a minute before putting them back. This forces the clock to search for the signal again.
- Give it a good spot for the night. Set the clock near a window, ideally one facing toward Colorado, and keep it about six feet away from TVs, computers, microwaves, Wi‑Fi routers and other electronics. Avoid setting it on a metal surface.
- Wait overnight. The signal is strongest late at night. Many clocks show a small tower or signal icon once they have synced. After that, hang the clock back where it belongs.
Still not working?
- Metal roofs, steel framing and thick concrete walls can block the signal. Try a different room or a higher floor for the first sync.
- You can set the time by hand in the meantime. The clock will keep good time and correct itself the next time it catches the signal.
- If an older clock still can’t find the signal after all of these steps, replacing it may be the easiest fix. Our atomic wall clocks and digital atomic clocks are a good place to start, and our atomic clock buying guide can help you choose.
Mark your calendar
Daylight saving time begins again at 2:00 a.m. on Sunday, March 14, 2027. If your clock is set up correctly now, it will spring forward on its own, with no ladder and no manual required.
