You can easily view a volunteer's availability and shifts while you're scheduling. Simply click on the volunteer's name in the schedule to open their profile card. The profile card will automatically open to the event in the 'Activity' tab, listing the volunteer's shifts. If the volunteer selected shifts during the signup process, those will appear in green. You can confirm, waitlist, and cancel shifts directly on the profile card.
Did you know you can also click back through the Profile card to the 'Forms' tab, right in the schedule, to see that individuals' form responses? Review their answers to your event signup form, and see when they signed up before scheduling them.