Arrival window: forty to sixty minutes, on event days too
For a same-day booking at a central address, she is at the door forty to sixty minutes after confirmation. The window does not stretch on busy event days.
The arrival window is the time the house works to for a same-day booking in the central districts: between forty and sixty minutes from the moment the booking is confirmed to the knock at your door. It is counted from confirmation, not from your first message, and it is the same on King's Day as on a quiet Tuesday.
Why it holds on crowded days
The women who work with the house set out from homes in the centre, the Jordaan, Oud-Zuid and De Pijp, so the journeys are short even when cars cannot cross the canal ring. And the reply only confirms an hour it can keep. If the streets between her and you are packed at the moment you want, you will be told so and offered a different hour, rather than a promise that would be broken.
What it does not cover
A room at a Schiphol airport hotel is outside the window and is arranged separately, with the journey time agreed first. An advance booking has no window at all; she arrives at the hour agreed. And the window covers her journey, not yours. On an event day the journey that goes wrong is usually the guest's own walk back to the hotel, which is why the guide to crowds and closures recommends writing once you are already on your way.
Early or late in the window
A knock at the forty-first minute and one at the fifty-ninth are both on time. If something follows the session at a fixed hour, count from the far end.