5 months for me, shaving everyday for the first month, then every 2-3 days after that.
After only 5-10 shaves at first, I was getting a decent comfortable WTG shave, and horrible around chin line and under nose, but the last months (im at 6 months now) I can comfortably do WTG, XTG and ATG shaves. Still struggle a bit with the chin/jaw line (to get BBS) but getting better week by week.