When the big hand's on "last call for alcohol" and the little hand's on "that dude's been here since happy hour".
"I got arrested last night at dick o'clock".
"I started macking on the last call beauty queen at dick o'clock".
"I stayed out last night till dick o'clock, and had a wicked bad hangover all day at work".
The time at the gay bar when all of the gays realize if they wanna get dick that night and still be able to make it to work the next morning then they better act fast.
This time (generally around 1am or so) is also, sadly, the time when all of the dutiful fag hags are left to their own devices as far as matters of socializing and transportation are concerned.
Made popular by Margaret Cho (well-known fag hag).
Sara: I had to take a $20 cab ride home from the gay bar last night!
Sara: Well, at Dick O'Clock Dave went on a Dick Hunt and left my ass!
Jarod: Well, it WAS Dick O'Clock - that's your own damn fault for not driving yourself. You know how we roll.