The Calendar You've Been Waiting For
This is a built-in feature. Simple add the following string your your dayback URL:
?kiosk=10#/
The full URL would like like this:
https://app.dayback.com/?kiosk=10#/
The parameter in the above example will refresh the calendar every 10 minutes. You can increase or decrease this as needed.
You can refresh the calendar from your own code by using the DayBack URL parameter refresh=true or by using this method in your JavaScript custom action:
seedcodeCalendar.get('element').fullCalendar('refetchEvents');
Check out related documentation on how to only refresh specific events in FileMaker.