Payment term with installment and complex condition

Hi Gurus,

I need some help to configure a new complex payment term with the requirements below

(I really don't know if it will be possible):

1) The baseline date going to be based in document date - there is no problem here.

2) The payment term has installments (OBB9 => 33% 30-days, 33% 45-days and 34% 60-days) - there is no problem here.

3) The net due date necessarily need to be in a day that is multiple of 5, like May 5 or July 10 (our customer requirement).

How can I apply this condition to the net due date?

Thanks a lot!