Contrary to popular belief, no federal rule mandates that U.S. states or territories observe daylight saving time.
So why is a transportation authority (Interstate Commerce Commission) in charge of time laws? It all dates back to the heyday of railroads.
"In the early 19th century … localities set their own time," said Bill Mosley, a public affairs officer at the U.S. Department of Transportation.
"It was kind of a crazy quilt of time, time zones, and time usage. When the railroads came in, that necessitated more standardization of time so that railroad schedules could be published."
In 1883 the U.S. railroad industry established official time zones with a set standard time within each zone. Congress eventually came on board, signing the railroad time zone system into law in 1918.
The only federal regulatory agency in existence at that time happened to be the Interstate Commerce Commission, so Congress granted the agency authority over time zones and any future modifications that might be necessary.
Part of the 1918 law also legislated for the observance of daylight saving time nationwide. That section of the act was repealed the following year, and daylight saving time thereafter became a matter left up to local jurisdictions.
Daylight saving time was observed nationally again during World War II but was not uniformly practiced after the war's end.
Finally, in 1966, Congress passed the Uniform Time Act, which standardized the start and end dates for daylight saving time but allowed individual states to remain on standard time if their legislatures allowed it.
There's lots more information about Daylight Savings Time but enough is enough. It's always hard to get used to the time change whether it's spring or fall.