The appointment written first can gain priority simply by occupying the space earlier.

Order of arrival often decides importance without anyone deciding anything. Once something is in the calendar it becomes the fixed point, and everything more important that comes later has to argue for a place around it. That is a scheduling accident presenting itself as a judgement about what matters.

Look at this week and ask which entries would still be there if you were building it from scratch today. Moving one thing that holds its slot only through seniority is often the fastest way to find an hour.