PS - For more on this see Old Christmas Day and be sure check out the Wikipediea entry for Christmas .

Yule, as with Easter, is a hangover from Anglo-Saxon times and as such was a moveable feast determined by the Moon (see the Wikipediea entry for Yule ), somewhat like Easter, which we celebrate on the First Sunday after The Full Moon following the Spring Equinox, which occurs half way between the Winter & Summer Solstices.