When should the patent opinion statement be sent back

Generally speaking, it takes four months for the first call, and two months for the second and subsequent calls. It will usually be explained at the end of the notice. Posting date (a) with the date of 15 is your receipt date (b) by default, and then the receipt date of 4 months or 2 months (b) is your final delivery date (c). If it is delivered directly or by courier, it needs to be delivered on the delivery date (c)