BEFORE MIDNIGHT it is necessary to check the Departures screen to ensure there are none left in the system. If departures are found, they will need to be either checked out, or their departures will need to be adjusted to the correct dates.
Leaving Departures in the system past midnight will adversely affect balancing and reporting within the PMS. These are referred to as Overstayed Reservations.
Overstayed Reservations will continue to deduct from your available inventory, but will cease to generate revenue on their scheduled departure date (ie. Room & Tax will stop posting). This can cause a situation where no revenue is being made on a room, while also appearing as unavailable to sell because a reservation is still checked in. Overstayed Reservations are easy to identify in the PMS as they will show up in red text.