Sunday brings the annual fall time adjustment across most of the United States, with clocks reaching 1 a.m. twice as the seasonal shift takes effect. The daylight saving period that began March 9 concludes Sunday, contrasting with spring's hour loss where timepieces bypass 2 a.m. completely – Sunday morning brings an hour gain, with clocks reversing from 1:59 a.m. to 1 a.m., according to NBC News. Earlier sunset times will begin appearing nationwide as late autumn transitions into winter months.
Standard time persists until spring arrives and the daylight adjustment resumes, with the next daylight saving period beginning March 8, 2026, and concluding November 1, 2026, NBC News reported. The Standard Time Act of 1918 established this system to maximize summer daylight by postponing sunset an additional hour, according to the Astronomical Applications Department of the US Naval Observatory cited by NBC News. Following controversy and quick repeal in 1919, World War II brought reinstatement from 1942 through 1945, with the 1966 Uniform Time Act creating uniform dates while permitting state opt-outs. The 2007 schedule of beginning the second Sunday in March and ending the first Sunday in November remains current.
Hawaii and most of Arizona decline participation, maintaining consistent clocks year-round, while American Samoa, Guam, Puerto Rico, the US Virgin Islands and the Northern Mariana Islands maintain permanent standard time, according to NBC News. Most nations implement some variation of "summer time," though not synchronized with American scheduling, with European and North American countries comprising most Northern Hemisphere participants. Approximately one-third of global nations currently observe daylight saving time, according to the Pew Research Center cited by NBC News.
The Senate approved the Sunshine Protection Act in 2022 for permanent year-round daylight saving time, but House advancement stalled, with a January Senate reintroduction similarly failing to progress, NBC News reported. Nearly every state has examined permanent time legislation, with 19 states enacting bills or resolutions over the past seven years, according to the National Conference of State Legislatures cited by NBC News. Federal law prohibits permanent daylight saving time without Congressional approval.
Research indicates year-round daylight saving time could decrease traffic accidents and criminal activity, yet numerous specialists oppose it because solar time dictates the sun should peak at noon, according to sleep researchers cited by NBC News. Sleep specialists favor the alternating clock system, noting morning darkness may elevate cortisol hormones, potentially increasing sleepiness, Dr. Kin Yuen, a sleep medicine specialist at the University of California, San Francisco, and a fellow at the American Academy of Sleep Medicine, explained in 2022, according to NBC News.
Extended evening sunlight during daylight saving time may delay bedtime, potentially postponing melatonin production in the body.
