Appointments Booking - General Settings
In the plugin admin menu under Options.
You can find several options to customize the calendar appearance.
First day of the week - defined which day will show first on the front view of the calendar. This settings it for all calendars defined.
Search for an open slot - define within how many days range calendar will look for an open slot when user load the calendar. Setting a high value might cause a slowness in calendar load in case the calendar is busy.
Discussion form page - This is a preselected page which is generated once plugin is installed and includes the shortcode for the discussion option. You can change this page while selecting another one.
General WordPress Settings
Some general settings are controlled by WordPress settings. The Date Format shown on the calendar and also the Time Format are taken from your WordPress site general settings.
if you want to reduce potential automatic spam request you should add a recaptcha keys in the plugin general setting. Once added all forms for all calendars will have reCaptcha at the bottom of the form