Thanks, since we have to return the car early the next morning and catch a flight, I wonder if it's possible to not count that day if we change it to the night before ?

If you're not returning the car at the airport, it's better to return it in the evening, so you don't have to look for a place to park that night. You also need to return the car with a full tank of gas. If you have a flight to catch in the morning, any delay in returning the car will be a problem. Or if there is a collision before you return the car in the morning, you don't even have to get on the plane. You have to think about it.

The answer comes with the question!

How can I input the four words "I will answer"?