Can I book an appointment with the GravityCalendar extension?
Short answer: Unfortunately, no.
Long answer: Our GravityCalendar extension is similar to a GravityView View layout, it allows you to display your form submissions on the front-end in a calendar format by using a date field on your form.
Here's a live example: https://try.gravityview.co/demo/calendar/
However, this extension doesn't have any booking functionalities that can be used on your form. For that type of feature, we recommend two plugins: gAppointments and Gravity Forms Inventory by GravityWiz.