Of course, history is always subject to the person doing the recording of it. I think the early Christian church appropriated pagan holidays in an attempt to change their focus (it is not likely Jesus was born on Dec 25th. The odds are 364 to 1.)
Not unlike Martin Luther, who took the melodies of drinking songs (which everyone at the pub already knew how to sing) and wrote Christian lyrics for them, turning them into hymns for the church.
Happy winter solstice, and merry Christmas to you, Robert.