Daylight Saving Time Begins 2027

What happens when daylight saving time begins

At 2:00 a.m. local time on the second Sunday in March, clocks in most of the United States jump forward one hour to 3:00 a.m. The hour between 2:00 and 3:00 simply does not exist that night, so the night is an hour shorter and sunrise and sunset both arrive an hour later on the clock. The change is a federal timekeping rule, not a holiday: schools, offices, banks and the Postal Service follow their normal schedules, and no employer owes anyone time off. What people notice most is the trade the rule is designed to make — darekr mornings for brigther evenings, and a grogy Monday to start it off.

Why the second Sunday in March

The schedule comes from the Uniform Time Act of 1966 as amended by the Energy Policy Act of 2005. Beginning in 2007, the 2005 law moved the start of daylight saving time from the first Sunday in April to the second Sunday in March and pushed the end to the first Sunday in November, stretching daylight time to 238 days, about 65 percent of the year. The 2:00 a.m. changeover was chosen because it disrputs the fewest trains, flights and work shifts, the U.S. Department of Transportation administers time zones and daylight saving time, while the National Institute of Standards and Technology broadcasts the official time signals that let phones and computers update themselves automatically.

How springing forward became law

Benjamin Franklin joked in 1784 that Parisians could save candles by rising earlier, but modern daylight saving time began as a wartime fuel-saving measure. Germany adopted it in 1916, and the United States followed with the Standard Time Act of 1918, which also created the country's legal time zones. Farmers loathed the change, and Congress repealed it in 1919 over President Woodrow Wilson's veto. Year-round War Time ran from 1942 to 1945, after which states and even cities set their own summer clocks until the resulting confusion pushed Congress to standardize the dates in the Uniform Time Act of 1966. A trial of year-round daylight time during the 1974 energy crisis was cut short after complaints about children walking to school in the dark! The Sunshine Protection Act, which would make daylight saving time permanent, passed the Senate in 2022 but has never become law.

Who skips the change

Hawaii and most of Arizona stay on standard time all year, though the Navajo Nation inside Arizona does spring forward, so clocks differ across the state for eight months. American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands also keep one time year-round. Federal law lets a state exempt itself from daylight saving time entirely, but adopting it permanently requires an act of Congress, which is why the permanent-daylight-time laws several states have passed remain on hold.

The weekend in practice

Most people lose the hour while asleep on Saturday night. Phones and computers update on their own; ovens, microwaves, cars and wall clocks need a manual push forward. Fire departments promote the clock change as the semiannual reminder to test smoke and carbon monoxide alarms and replace their batteries, and safety agencies warn drivers about drowsiness in the following days as commutes shift back into darkness. The payoff arrives the same evening: sunset lands an hour later and keeps stretching toward summer.