Journey time to a room beside the airport
Journey time is the travel to a room at Schiphol, Schiphol-Rijk or Schiphol-Oost, agreed with you in writing before anything is fixed, not a set window.
Rooms in central Amsterdam run on a fixed arrival window. Rooms near the airport do not, and the term used for them here is journey time. It is the time it takes to reach an address at Schiphol, Schiphol-Rijk or Schiphol-Oost, and it is agreed with you in the thread before any hour is fixed.
Why it is not a standard figure
The airport hotels are spread across a wide area, from buildings joined to the terminal to others a shuttle ride out along the business parks. The time needed depends on which one you are in and on the hour. Rather than promise a number that would be wrong half the time, the house agrees a figure for your particular booking, and the session is fixed only after you have accepted it.
What it means in practice
Write earlier than you would in the city. A message from the arrivals hall or from the train platform, naming the hotel and the hour you want, gives time for the journey to be agreed without pressure. Every booking at an airport hotel carries a deposit, and the rates are the same as in town.
The airport hotel area page describes the cluster in more detail, and the cluster entry in this glossary explains what the term covers.