Starting from the moment you performed your checkout, the client has 7 days to respond to your checkout. If this term has expired, then the system will automatically approve it. Please note, if the system approves your checkout, a rating will not be given. If your checkout is approved you will receive (incase you choose this option) your money within 3 or 5 working days.
For example: Did you checked out on Monday? Then the client is able to respond to it untill the next Monday. Does the client not respond to it ? Then the system will approve your checkout the following day, in this case Tuesday.