Damn, Christianity is weird:
The Feast of the Circumcision of Christ is a Christian celebration of the circumcision of Jesus in accordance with Jewish tradition, eight days (according to the Semitic and southern European calculation of intervals of days) after his birth, the occasion on which the child was formally given his name.
The circumcision of Jesus has traditionally been seen, as explained in the popular 14th century work the Golden Legend, as the first time the blood of Christ was shed, and thus the beginning of the process of the redemption of man, and a demonstration that Christ was fully human, and of his obedience to Biblical law.
The feast day appears on 1 January in the liturgical calendar of the Eastern Orthodox Church. It also appears in the pre-1960 General Roman Calendar, and is celebrated by some churches of the Anglican Communion and virtually all Lutheran churches.