System auto prompt due date when workbook is open

Dear All,

Someone have help me write a macro to prompt me on over due payment.
But instead of clicking on the "CHECK DUE DATE" button, can the
macro auto check due date whenever I open the workbook?

Here I attached the workbook for easy understanding.

Hope and need your help urgently.

Thank you very much =)

It is password Protected.

Vikas B

Dear All,

Password is 789789
I reattached without password.

Dear royUK,

If I not wrong, Conditional Formatting only highlight the over due row for me.
It wont alert me the over due invoice no.
As it will be a 1000++ - 3000++ record, therefore, it will be difficult to scroll for checking

Hi, Since there already have a macro to prompt in a window said if overdue.
Is it possible to request the macro to prompt once I open the workbook instead of click on a button?