from the minute you agree to meet up with someone, the hook up clock is ticking. for everyone its a little different. if your the one traveling, you hook up clock is going to be decided based on estimated time to get there, and will be decided quickly.
Once the traveler leaves, the hosts hookup clock is ticking. This vairies from person to person, however sometimes (we call them flakes) the hookup clock is too short, and they tell you to fuck off before you get there.
the hookup clock is evil. especially when its too short. Like when someone lives in long beach and you tell them it will be like an hour before you get there, they tell you thats cool, then you get down there and they flake and then you have to spend another hour coming back to hollywood cuz you got nothing better to do. Yeah, fucking time of my life.