When a client or business user goes to schedule or reschedule an appointment, time slots for all of the existing appointments are removed from a list of all possible time slots on that date, leaving just the available time slots. When the schedule is linked to another schedule, then the existing client appointments from both schedules are removed.
For example, a massage therapist wants to schedule new patients at a few specific times during the week. They set up two schedules one for existing patients with hours from 9:00-5:00 everyday and the second schedule for new patients with times on only Mondays and Wednesdays at 3:00. By linking the schedules, new patients are restricted to these times, but the new patient time slots can be filled by either new or existing patients on a first-come/first serve basis.
Where: Settings > Schedules and Work Hours