The system defaults automatically to EST. However, you can change the display time to your personal time zone within the settings of your back office account.
To do that: log in to your account, Go to My settings, then select Calendar. You will find time zone option in the drop down menu. Select yours and click on SAVE button.
The screen will advise you that your changes have been made. Once that is done, all appointment times will show in the time zone you selected.