I was offered the chance May 16, and had it confirmed today on the 24. So about a week to have it confirmed.
It seems like a good idea to not bet on the change at first though. My recruiter said something along the lines of "throwing it up and seeing if it sticks," so I didn't start making any plans or changing anything until I was confirmed. Other than stepping up my PT a bit due to the motivation of having 40 days chopped off of my wait.