Hello, Oluther2. 

Thank you for taking the time to read the thread. You can set your payment terms to the Date Driven method. This will allow you to enter the day of the month that a payment is required within the due date.
For example: Your invoices are due on the 25th day of the month and you give your customers a 1% discount if they pay before the 10th of the month.
 

For the date Date Driven terms, follow the step-by-step process in this article and proceed directly to the Date Driven section. 

I'm always around to help you with your questions. Have a good one!