@RadicallyRooted - For your vacation time, if you block it off in your calendar, it will not be available for Scheduler to book. You can also go into your Scheduler configuration, though, Edit the settings for any schedules you have active, go to the second tab (Availability) and select 'Date Override' to change the availability of specific dates.
Once the meetings are schedule, they are no longer managed by the scheduler app, they are managed by your calendar. If you go directly into the calendar, you can cancel those appointments, and your calendar should send them a notification that the appointment was cancelled and any message you need to send with the cancelation.
