In news from across the pond, it is Stir Up Sunday, the Sunday before the first Sunday in Advent. Project Britain explains:
Before Christmas puddings were sold ready-made in foil containers, they were always made at home.
They were made a month before Christmas day so the flavours had plenty of time to develop before Christmas.
On Stir-up Sunday families returned from Church to give the pudding its traditional lucky stir. The pudding mixture was always stirred from East to West in honour of the three Wise Men who visited the baby Jesus. Whilst stirring the pudding mixture, each family member would make a secret wish.
On their way back from church, children were often heard chanting the following rhyme:
Stir up, we beseech thee, the pudding in the pot;
And when we get home we’ll eat the lot.
These words were an adaptation of what they had heard in church on this day.
There’s more here.