Determining the specific date of Christ’s birth has been an earnest pursuit of believers since the early Church fathers. Even today we struggle to know the actual birthdates of living people from rural settings. My wife’s grandfather has official documentation stating he is 93 years old, but he believes himself to be 95, based on what his mother told him. That said, the September date has a strong likelihood. Also, he was likely born around 3 BC - the transition from BC to AD was sort of a guess.