Also, with the 7 days after, I am never sure about that because of the weird way the IO can count.
For example, if the due date is the 10th, 7 days after would be the 17th.
I am never totally sure about that as they may count the due date as the 1st of the 7. So I would always make sure that I report on the 16th at the latest to be on the safe side.