You can currently book on RCI through about the end of August. (date changes daily) However, it seems the RCI inventory fluctuates rapidly. When we were booking for May, in the space of 2 hours, I saw 3 rooms at AKV pop up, then disappear, then 3 more pop up.
I was told by a consultant at RCI, if you find something you think you like, you better snag it. you have like 24 hours or so to cancel and get a full refund if you decide you don't want it.