I've arranged a 3 night trip to a UK destination including Avis car hire. Looking at the Avis paperwork the collection time is when my flight arrives shortly after 9AM, and the return time is down as shortly after 1PM, apparently calculated as 2 hours before return flight departure. I'm planning to get to the airport by then, but realistically I could still catch the flight if I turned up an hour later. If I did would this count as returning the car late? Since cars are normally hired by the day I'd have thought that even if I missed the flight Avis wouldn't worry providing the car was returned that day.