Sometimes in the bible events are described in a simple declaration without explanation that part of it is for the present and part of it is future, Peter quoted Joel pertaining to the outpouring of the Holy Spirit(something that happened at that time)AND the signs and wonders(which have not yet happened) and there was no distinction made between the present and the future, even though there was a present fulfillment and a future fulfillment. Peter certainly knew that the outpouring of the Holy Spirit was taking place and he was certainly aware that the signs in the heavens were not taking place, yet he quoted it all in one statement because that was the way it was written. Much of the bible is written in this fashion and we just have to recognize it.