I note the US tried permanent DST in 1974 and didn't like it.
It didn’t even last a year. Enacted in January, repealed in October. Leave it to the two dumbass senators from Florida to want to repeat the mistake.
So, the US
didn't try permanent DST in 1974, and didn't like it.
It's not possible to try it in less than a year.
Of course it’s possible. They switched to DST in January, and people hated it. In October, they switched to standard time on the usual schedule, because they didn’t want to go through a
second DST winter.
Given that they weren't planning to switch in January ever again, people hated something that wasn't part of the proposal they rejected.
If they still hated it in January '75, having been on DST for a full year, their opinions may well have been very different.
So no, they didn't try it. And no, it isn't possible to try it in less than a year.