The arrival window: forty to sixty minutes
The arrival window is the stretch of time in which she reaches your door. In central Amsterdam, it is forty to sixty minutes after your booking is confirmed.
Here, the word window does not mean glass. It means a stretch of time with a start and an end. She will knock at some moment inside that stretch. The window exists because a journey across a city is never exactly the same twice. Traffic, bridges and trams change a few minutes each time.
Working it out
Take the minute of your confirmation and add forty. That is the start of the window. Add sixty instead, and you have the end. A confirmation at 20:15 gives a window from 20:55 to 21:15. A confirmation at 23:30 gives a window from 00:10 to 00:30, on the next date.
Be ready at the start
Plan to be ready at the first minute of the window, not the last. Have your phone near you, with the sound on. If the building has a street door, be ready to go down.
Outside central Amsterdam
For Schiphol and the airport hotels, the window above does not apply. Her journey time is settled with you in the thread, and only then is an hour set. The page on outcall explains where she travels.
If the window is passing
Traffic or a bridge that is open for a boat can push a journey towards the end of the window. If sixty minutes have passed and nobody has knocked, write one line in the booking thread, and the house replies with an update. Do not book a second therapist in the meantime, because two visits would then be heading for one room.
The window and your plans
Keep the hour after the window free. A dinner table or a call set for that moment will cut into the time you have booked.