Is it possible that a Purchase Order revision that is in the process of being changed lines items de

When a revision is being done to purchase order line items the buyer sometimes forgets to change the encumbrance period on revised line items to the current month which are causing error messages.  Is it possible to have the current month encumbrance period default on revised line items before they are put into the approval path?  The purchase order encumbrance defaults to the original date of the encumbrance.