"If I could have seen you by the end of next month, it would have made me very glad"
To my way of thinking, there seems to be no grammatical problem in this sentence, because "could have p,p" can refer to the future event according to context, but it seems like a lot of native speakers tend to object to this usage of "could have seen". I know we use "could have done" usually in the past, not the future, but in this combination "could have seen + by the end", can "could have seen" be used to refer to the future event?
What do you think?