I have used park and jet many times but have a question anyway. on my next trip my return flight lands at 11:40 pm. this means I will not be getting my car until around 1am. Do I have to pay for an entire day because it is past midnight?

It is calculated by your entry and exit time as 24 hr days. So depends on when you pulled in. Start calculating 24 hour days from that point.

You pay based on elapsed time, i.e. 7AM Thursday to 7AM Friday equals one day.

It's calculated by your entry and exit time.

Goes by time