It was originally sort of a joke
That’s right! Long before the plan was ever adopted, Benjamin Franklin wrote a satirical essay in which he hinted at something quite similar as a way to save money by people conserving candle wax! Well, over a century later, the idea actually happened and I’m sure Ben would have been pretty shocked to see the idea taken seriously.
WWI is to blame for it becoming a law
In order to conserve coal, Germany put the law into affect. As other countries needed to save for the war effort, they adopted. As was true with the war, America didn’t adopt until a bit later. And thus, the whole world was in war and doing daylight savings time!
There is a place in America that do not participate
Arizona actually does not participate in the Daylight Savings Time which has got to be confusing for travelers to and from the state! Because the state is already so sunny, they don’t wish to gain anymore. But this means that the time zones for Arizona change every half the year!