Originally Posted by Frozenguy

I use this weekly. I figure i need about 30 min margin for traffic, and then i give myself extra time incase i need to rebook my return. so if i expect to get to the garage at 11am, i give my self 30 min margin down to 10:30am and then the 4 hour grace means i start the reservation at 2:30pm and ends at 2:30pm on my exit day or the following day if my exit is sufficiently past 2:30pm on the actual date. then i can leave by 4:30 wihtout extra charge.