Updated on: March 9, 2025 / 7:04 AM EDT / CBS News
Daylight saving time in 2025, when clocks change by an hour, has begun. Here’s a look at when exactly we “spring forward” and how daylight saving time works.
What time exactly does the time change for daylight saving 2025?
The time change took place at 2 a.m. on Sunday, March 9, moving ahead to 3 a.m.
How does the time change work in the spring?
In the spring, the clocks move forward one hour, meaning the sun sets an hour later in the evening and rises an hour later in the morning.
Digital clocks like the ones on cellphones will automatically change. Analog clocks and any clocks or watches that do not automatically adjust will need to be reset manually.
With the change, we lose an hour of sleep.
Medical research has shown this shift is associated with a number of health concerns, including an uptick in strokes, heart attacks and traffic accidents in the days following the time change.
When does daylight saving time end in the fall?
Daylight saving time ends this year on Sunday, Nov. 2, when clocks will “fall back” one hour. With that change, the sun will set an hour earlier in the evening and rise an hour earlier in the morning.
Which countries do daylight saving time outside of the U.S.?
Outside the U.S., most of the countries that observe daylight saving time are in Europe, where it’s common, according to the Pew Research Center. France, Italy, Spain, Germany, the United Kingdom and Switzerland are among the countries where it’s practiced.
Daylight saving time is also observed in some parts of Canada and Australia. In Africa, Egypt is the only country to observe it.
Which U.S. states don’t do daylight saving time?
Hawaii and most of the state of Arizona do not observe daylight saving time, according to the Department of Transportation, which oversees time zones in the U.S.
Daylight saving time is also not observed in the U.S. territories of:
- American Samoa
- Guam
- Northern Mariana Islands
- Puerto Rico
- U.S. Virgin Islands
Who invented daylight saving time?
Some have said Benjamin Franklin started the practice in 1784. He wrote a satirical essay for the Journal de Paris proposing regulations to ensure early risers.
Philadelphia’s Franklin Institute, however, disputes the claim, and looks to New Zealand entomologist George Hudson, who proposed a two-hour clock rollback in 1895. The suggestion was inspired by his passion for collecting bugs, as he wanted more light after work to gather insects.
Still others credit British builder William Willet, who wrote a pamphlet in 1907 that encouraged moving clocks forward in the spring so that people could get out of bed earlier. Lighter and longer days were supposed to save energy, reduce the number of traffic accidents and help people be more active.
In 1916, during World War I, Germany became the first country to practice daylight saving time to conserve fuel, according to the Congressional Research Service. Other European countries soon followed, and the U.S. started practicing daylight saving time in 1918 to add additional daylight hours and help conserve energy.
Today’s practice of starting daylight saving time on the second Sunday in March each year and ending it on the first Sunday in November was enacted under former President George W. Bush.
Caitlin Yilek and Cara Tabachnick contributed to this report.
Sarah Lynch BaldwinSarah Lynch Baldwin is a deputy managing editor of CBSNews.com. She helps lead national and breaking news coverage and shapes editorial workflows.
