When one initially creates an appointment time block, it is easy to forget to subdivide the time block into slots before publishing the appointment.
I’ve made this error more than once; I wonder whether others make this mistake as well, and whether the UI could somehow be improved to encourage the user to split the time block before creating the appointment. Furthermore, I still don’t understand why a time block cannot be divided into slots after the appointment has been created. When this mistake has been made, currently the user has to delete the appointment and start over again, which is a real inconvenience.
The current UI is also problematic: namely, after editing that appointment, although the first time block is grayed out, with only one time block displayed, the “create slots” button is not grayed out, contradicting the idea that that initial time block can’t be divided. For consistency’s sake, that “create slots” button should only become active when the second time slot is created, and not before. In other words, if only one time block is displayed, both the time block and the create slots button should be grayed out.