A divisional renewal-fee deadline

A fictional European divisional application is filed on the fifteenth day of May. Renewal fees for earlier years have already become due for its parent application. For this exercise, the applicable current rule gives a four-month period from divisional filing to pay those already-due divisional fees without an additional fee. It also allows late payment with the required additional fee within six months from the divisional filing date. Ignore holidays and office closures in this supplied model. An administrator calculates the late-payment limit by adding six months after the four-month period ends. Students must identify the triggering event, compare the two periods and avoid turning them into a ten-month combined period.