Neurologist Dr. Ptacek explains how "falling back" disrupts the 24-hour circadian clock, affecting mood and performance, with mitigation tips.

(NEXSTAR) — If you’re reading this outside of two specific states, the digital clocks in your home have likely fallen back an hour (though maybe you didn’t even notice). Daylight saving time officially came to an end at 2 a.m., kickstarting our multimonth observance of standard time.

Fall’s time change can disrupt your body’s internal clock, leaving you tired in the morning and wide awake at night. Dr. Leana Wen explains how to cope.

California, with clocks resetting to 1 a.m. Pacific Standard Time. Most of the United States will “fall back” to Standard Time on Sunday. Only Hawaii, most of Arizona, American Samoa, Guam, Puerto Rico and the Virgin Islands do not change with the rest of the country as they are always on Standard Time.

When do clocks fall back 2025? Americans will turn clocks back one hour as daylight saving time ends at 2 a.m. Sunday. The time change marks the return to standard time until March 8, 2026. Learn how this affects sleep,