Some fucking news site I copied this from wrote:
25 December has long been associated with the birth of Jesus owing to its proximity to the winter solstice.
The winter solstice is the point of the year when sunlight hours begin to increase once more after months of decreasing, leading to the notion of ‘longer days’.
The event holds symbolic theological significance as Christians see the occasion as representing the Light of Christ entering the world during the darkest of days.
Its some religious bollocks for it being the 25th aka correct and if you say otherwise you are going against jesus, have fun burning in hell with saddam hussein you wrongens