Our Booking plugin follows per night logic. However, we have one Addon for the Booking plugin named as "Rental System Addon" which follows per-day logic. This addon has two settings "Flat charge per day" and "Allow same day booking" which will allow the same day booking and it will charge based on the number of days not based on the per night logic. You can select the same date as the start date and end date.
For a detailed description of our Rental System Addon, you can go through the below documentation.