Notice: the time between your message and the hour
Notice is the warning time you give: the hours between your message and the booked hour. More than twenty-four hours of notice means a cancel costs nothing.
The word notice has several meanings in English. A notice can be a sign on a wall. To notice means to see something. In a booking, notice means warning time: how long before the booked hour you tell the house about a change.
How it is measured
From the moment your message arrives in the thread to the booked hour. A message at 19:00 on Monday about a booking at 21:00 on Tuesday gives twenty-six hours of notice. A message at 22:00 on Monday about the same booking gives twenty-three.
Why it matters
Notice is the only thing that decides what a cancel costs. With more than twenty-four hours, the whole deposit comes back. With less, and before she has left, half is kept. After she is on her way, the whole deposit is kept. The cancellation entry lists the three steps.
A tip
Count the hours on the twenty-four hour clock, in Amsterdam time. If your phone is still on the time at home, the count can be wrong by several hours, and that can move you from one step to the next.