OK, now, after however many years of tradition, I can see that 9-5 has developed a certain amount of institutional inertia, and that we’re not likely to easily change it. But that wasn’t always the case. How did it come to be the standard in the first place?
Now THAT’s a question. I can venture only guesses. I’d assume that this began with banking hours and that people sort of conformed to those. I pray someone swoops in with the answer before I have to post this question as a new thread.