Without detailed satellite photography, we will probably only know once the superstructure is up in shape in-general. With detailed satellite photography, we can mostly figure out by measuring the dimension of the ship's hull and comparing with past observations.
Speaking of detailed duration (months, weeks) - Unless we got someone working in the shipyard or someone from the PLAN that's related to the project here in this forum, there is little viable answer. The best we can actually obtain for most of the time are rough guess-timations.
So I'd suggest keeping expectations low when it comes to PLA-watching. Don't expect intricate, detailed information to surface themselves for at least some time - Or more often than not, for a very long time.