I always wondered
Why do we change the clocks?
The Simple Answer
Because a federal law sets daylight saving time and most of the country follows it. For places that do, the clocks move forward one hour on the second Sunday in March and back on the first Sunday in November.
Moving the clocks forward in spring shifts the daylight toward the evening by the clock, and moving them back in fall shifts it back. That is all daylight saving time is. The interesting part is the law behind it.
What the law says
The Uniform Time Act of 1966 set one national pattern. If a state observes daylight saving time, it must start and end on the dates in the law. A state may choose not to observe it at all, as long as the whole state does the same. In 1972 the law was changed so that a state split between two time zones could exempt the part that lies in the other zone. The Department of Transportation looks after it.
In 2005 the Energy Policy Act lengthened it. Daylight saving time now starts on the second Sunday in March and ends on the first Sunday in November, and it has been that way since.
Who does not change the clocks
- Hawaii
- Most of Arizona
- American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands
How much of the year it covers
In 2026 the clocks go forward on 8 March and back on 1 November. That is 238 days, or about 65 percent of the year. Many people think of daylight saving time as the short season, but it is the long one. Standard time, which most people call "winter time", covers the remaining 127 days.
Days Until Calculator: Count the days until the next time the clocks change, or any other date.