The overnight, when a stop crosses the whole night
An overnight is eight hours of company with one therapist or two, arranged ahead, confirmed with half the fee and suited to a night stop.
Some layovers are not gaps between flights at all but nights between them. The overnight is the format for a traveller who has the whole night in a room near the terminal and would rather not spend it alone. It runs for eight hours and is not eight hours of massage: it holds a session early in the night, then sleep, then a quiet start to the morning.
The figures
The night is priced as one block rather than as eight separate hours, and the block moves with two things only: whether one therapist or two comes, and whether one guest or a couple holds the room key. A couple sharing one therapist pays exactly double the solo night. Half of whichever figure applies goes ahead, as it does on every overnight and on every airport booking.
When it suits a traveller
It suits a stop where the onward flight leaves after breakfast and the arrival came in the evening, when the choice is between an evening session and a night with company. For many night stops, two hours early in the evening followed by sleep on your own is the more practical trade, and the overnight page sets out the difference. An overnight is arranged well ahead rather than on the day, because eight hours of anyone's time does not appear at short notice.
If the morning flight is early, the overnight ends when you need to leave for the terminal, and the start is set to make eight hours fit. The deposit entry explains how the advance half is paid.