Permanent DST was implemented in 1974. It was supposed to be a two-year test. People hated it so much the government canceled the test after only a few months.
I was there. It was pretty depressing, going to school in pitch darkness, with that darkness outside the school windows lasting until after 8:30.
I would love more personal experiences to be shared about this time.. My parents were in middle school, so they don't really remember it much