Bookings — Moving one, and who gets told
Two things happen when you move a booking, and both are easy to take for granted until they go wrong somewhere else.
It keeps the length it was booked with. A haircut booked when that service was 90 minutes stays 90 minutes when you move it, even if you have since changed the service to two hours. Bookings you have already taken never shift under you, which is what makes last quarter's schedule still true.
The customer is told. A moved booking sends an email showing the old time struck through above the new one, because the first thing most people think is “was that always when it was?” A cancellation says who cancelled it. And both report back who was actually told — if the booking has no email on it, you are told nobody to notify rather than being left to assume a message went out.
Cancelling sets your own cancelled status, whatever you happen to call it, so the booking stays visible as a cancellation instead of vanishing from the day it was on.