Syncing Google Calendar event to Appointments+ plugin

I've successfully set up the plugin and synced with Google Calendar on our website californiasafetysolutions.com. However, we'd like to block off dates through Google Calendar and have that show up on the front end of the website. Is this possible, or can it only be done through the plugin settings? My client is only comfortable with Google Calendar, and wants to be able to use it to block off unique dates he won't accept appointments.