A dr told me that the scar will be healed in 6 months and cannot get any more "healed" with time so anytime from 6 mnths onwards. But it seems everyone is different. I think it also depends how well you were sewn up afterwards and if the dr put you back together well or not. When I had my 2nd CS the attending told me afterwards that the first CS scar was really well done and the previous Dr had done a good job.