Sales order : blocking approvals based on the credit period, not the credit amount

Summary:

Sales order blocking approvals based on the credit limit amount but we have business requirement it should be based on the credit days.

Content (required):

Customer accounts level we will give credit period days as 100 and customer account reaches credit period 100 days (calculate credit days from the invoice date) and amount not received means next sales order should not allow to complete and invoiced. The condition must be fixed only for the credit period, not the credit amount. An option must be given to unblock the customer if there is an emergency to invoice or raise a sales order.