Schedule oncoming appointments while planning

Hi Brooke,
I’ve done the homework for September and choose a goal, write every task and calendar them.
However, some of the tasks are appointments I’ve not scheduled yet because of other tasks that need to be done before.
How do I plan my entire month if I don’t know when the future appointments will take place?
Should I keep days open in my calendar for possible appointments or should I reschedule the tasks when I know when the appointments are or should I plan week by week?
For now, I choose the third option but I would love to hear your thoughts on this.
Have a great day.