Carbon-dating Christmas

Via Open Book, I saw this link that provides an argument for the bracketed Christmas-season (Dec 25-Jan 6) in use in the Church calendar (if you belong to a church that uses one), that IS NOT of Pagan origin. It still does not mean that Christ was absolutely born on Dec 25, but that the use of this date and the date of Epiphany are of Christian origin. I don't know how true this is, and if someday I am so motivated to research it further than this and Wikipedia, I will.