This last Sunday before Advent is known as Stir Up Sunday due to the Book of Common Prayer collect for today. This old name is much used now as it is linked to the idea of stirring the Christmas pudding although most puddings will have been maturing for some time.
Many Anglicans can expect hear that old prayer today immediately after communion.
Stir up, O Lord,
the wills of your faithful people;
that they, plenteously bringing forth the fruit of good works,
may by you be plenteously rewarded;
through Jesus Christ our Lord.
So today is not Christmas but the end of the liturgical year when we celebrate Christ the King. It is the climax of the year we began on Advent Sunday twelve months ago.