Sure, what you'd want to do is set up a system event to display a message at the time of check-in.
Here are the steps:
<FirstName> <LastName>'s birthday is this month! (<Birthdate>.)
Test a check-in for a patient whose birthday is this month.
If you want it to be more specific to if they have their birthday that day, I can do instructions for that as well.
I can also give you a call to assist with this setup if you'd like.
In order to have a pop-up message for patients who are in collections, you will need to mark them as in collections using the Account risk box.
If you are unaware of where this is:
To create the pop-up message:
At this point, as long as a patient has a "C" in their account risk box, the message should display when the appointment is being created.
If you have any issues let me know and I would be happy to give you a call and connect to help set it up.