What is described by the OP can be possible. In the 1980's, a means-limited college student I knew occasionally rented a vehicle on Friday night for the weekend from a convenient downtown location that was closed after Saturday mornings. He did figure out that returning the vehicle even as late as early Monday morning (by 6am) was quite sufficient. In any case, if they had the ways and means to charge him for an extra day, he would not have been any worse off. (On a holiday weekend, early Tuesday morning might even have been possible).
He used this concept in another city, but things didn't quite work out as alluded to in a subsequent post because that location did have staff that came in while the office was closed. By that point, he was "shocked" to be charged more for the extra day(s), having now become "used to" the concept, but of course did not object.
So, sometimes things are possible, and sometimes they're not.