We used to hit a Denny’s in the Inland Empire (CA) on the way to the desert for target practice, at about sunrise, after we had been on the road for an hour. The waitresses referred to that time of day as “the changing of the guard”. I gathered they liked the 2nd half of the guard, better.
I have a family member who once had to wait tables at Denny’s overnight, and fights happening after the bars closed was a virtual certainty at least a couple of times per week.