When adding an event on the calendar, ARMS will automatically review the calendar of all attendees listed and show you any potential conflicts they have with the event you are creating.
This reviews all Countable and Non-Countable events (e.g. Practice, Class, Athletic Training Appointments, etc.) and will denote what event(s) conflicts with your new event.
You can choose to either update the date or time of the new event in order to ensure all participants can attend, or you can choose to remove all attendees with conflicts so that only those who are available are added to the event.