In all of the Anglophone world, except for the United States, it's Boxing Day.
I can remember when the biggest disappointment, for some kids, was getting a toy they couldn't use on Christmas Day because it didn't have the required batteries. Because stores were closed, gratification had to be delayed until the following day, when those Eveready C and D cells could be bought.
Things are a bit different these days:
Kid, you plug your feet onto the pedals!
