I learned a long time ago to not put a time limit on a job. Something ALWAYS happens.
I do remember one time, at an oil change place I worked at. I did office stuff mainly, but in a pinch I could do anything. This time it was 5 minutes to close, and we had a policy of accepting customers until close. Woman pulls in, wants an oil change and "Please check everything out, I'm making a 300 mile trip."
I was not the typical, "lets see how much we can sell" kind of person you find in many of those places, but her belt was about to let go, I mean, there were chunks coming off. I show her, and she asks that we change it. As I'm pulling the tensioner lose from the belt, "SPRANG," it goes flying in all directions. It's now 15 minutes after close and, of course, we don't stock tensioners. Nearest parts store is 30 minutes away and does not deliver after 5... Almost an hour and a half later, we left...