It is Boxing Day, a statutory holiday in much of the English-speaking world. In Victorian times, servants got the day after Christmas off to spend time with their families, often with boxes of leftovers and annual bonuses. Since it is supposed to be an extra day off work, when it falls on a weekend it automatically shifts to the Monday.
But it has become the Canadian/ British/ Australian version of Black Friday.
The original idea made some sense; the Victorian gentry couldn't do anything without servants, certainly not cook up a Christmas dinner, so all their staff worked Christmas Day and got the next day off to spend with their families. They took away their annual bonuses, gifts and leftovers, while gentry ate cold cuts prepared the day before.
The churches opened up their alms boxes and distributed the contents to the poor; there was also a tradition of keeping one unopened gift and donating it to charity. Many people today work in food banks, donate excess gifts to the poor and make a point of polishing off leftovers.
Boxing day in Australia: ABC News
It was a holiday about equity- ensuring that everyone got a day off, even those who had to work on Christmas. It was a real buy-nothing day; you were supposed to use up what you had left over and give away what you didn't need. It was the exact opposite of the orgy of consumption that it has become.
It's a shame that its original meaning has been lost.