Answer: The module works in hours, and day is 24 hours long.
If we take the example below;
RENTAL COLLECTION DATE AND TIME: 19/06/2023 09:00
RENTAL RETURN DATE AND TIME: 26/06/23 17:00
Total Hours = 176 hours.
176 / 24 = 7.333, greater than 7, and the module will round this up to 8 by design, as it is more than 7 days.
Basically the same as if you return a rental late, you are charged the additional day.