Parking Garage Ticket Leeway

So you know those parking garages where you take your ticket with you and pay the cashier before going back to your car. My question is, how much leeway do they give you between paying and leaving the garage? What happens if you pay, then run into a friend and talk for 10 minutes? When you try to insert the paid ticket in the exit gate, will it get rejected? Or is it just paid for and done and that’s all it keeps track of? Then could you come back to the cashier like an hour after parking, then leave your car there for 3 more hours? Would that work? Where’s the cutoff?

I dunno, I always wanted to experiment but was too afraid to try.