Interestingly, this is an enumerated power under the U.S. Constitution. Article 1 section 8 explicitly grants Congress the power to "fix the Standard of Weights and Measures".
Not exactly, they do not have complete control. States can choose their timezone, they can choose whether to adopt DST or not. They cannot choose to switch to DST all year round though.
Can't they just move to the neighboring time zone and not adopt DST? (i.e. If California wants permanent summer time, they can switch to MST and sync up with Arizona ("America/Phoenix"))
Texas has, in recent years, changed the dates at which they adopted DST more than once (it was something to do with Halloween trick-or-treating and candy lobbyists).
edit: to answer my own question: there are some rumors about candy manufacturers influencing legislators to implement dst after Halloween so more children would partake and they would make more money. Doesn't seem to have anything to do with Texas in particular and might not be true at all.
But please correct me if I'm wrong.
Even then the states don't really have control. Me and my friends can decide to do whatever we want. We listen to the government because it's hard to coordinate and no one else has stepped up. No one really has any control.
In practice, yes they do have control. If Oregon decides tomorrow to officially give up DST, then everyone in Oregon would start using that new time zone.
Not sure what point you’re making other than that in general, the existence of states depends on people recognizing them and following their rules, which is true but doesn’t have much to do with DST specifically.
There already exists at least one US member state that doesn’t practice DST: Arizona.