How to Pay after 1st discount date but before Due date

Can you help answer this AP payment question? Need to know if we can achieve this in AP.

Lets say we have a vendor with terms like 2% 15 NET 30

Invoice came in May 1^st 2015

1^st Discount date – May 15^th 2015

Due date is May 30^th 2015.

This invoice came in late and we entered it yesterday on 21^st May.
Since we missed the 1^st discount date, now this invoice will be selected for payment on 30^th May cycle.

How can we get this invoice to be picked up in todays cycle (I know we can manually setup to pick this up but I want the system to pick it up naturally. Is their a