Once you off-rent your machine, the time of your rental stops. If there is a gap of time between when an off rental is confirmed and when the machine is picked up, you will not be charged for that time. The machine is still your responsibility, however, until it is picked up.
Rental prices are charged by the day, week and month. If you end your rental before the start of another day, you will not be charged for that day even it if takes a few hours for the machine to be picked up. If you continue to use the machine, over hours charges could be applied to your invoice.