To see your upcoming appointments, just click on your Calendar page. To see your past appointments in the Day, Week, and Month views, click the backward arrow on the left side of the date.

You can also switch to the Agenda view by clicking the dropdown menu on the upper right corner of the Calendar page. Then you can now see and click the "Past" button. Your old appointments will stay in your account forever. 

You can also click "Add a filter" to add filters for appointment status, locations, staff, services, and labels. You can even search for a customer's appointments using their name, email address, or phone number.