Unfortunately, that's a "Piece Of String" question. It can vary - you are waiting for a colony of bacteria to grow to a sufficient size that they will process all the nitrite produced by the other set of bacteria. Starting from scratch, that can take a couple of months, but you're probably part way along that road - I just don't know how far.
You should find in a awhile you can go two days without changing. Then 3 days, and so on. When you can go for 7 days without changing, then you are cycled, and you should then adopt a weekly 30-50% water change routine.