Banks

.The due date is the day you have to pay payment by. If you don't pay by the due date then you will be past due. Overdue means the same thing as past due.

You can relate the above term with the example of how we say 2.45pm and 3.15pm. for saying 2.45pm we say it's quarter to 3 pm and for saying 3.15pm we say it's quarter past 3pm.

I hope you are clear.