Line items can have a "Due date" associated to them.  If the due date is in the future, it should not count towards a team or user's OUTSTANDING balance - the outstanding balance is just that: the amount that the team or user owes right now.  So if the due date for a line item is in the future, they do not owe that amount yet, so it will only reflect in the total balance, not the outstanding balance.  Once the current date passes the line item due date, that amount will reflect in both the outstanding amount AND the total amount.