What
IS Boxing day?
http://www.web-holidays.com/boxing/ says:
In England a long time ago…
"Servants were required to work on Christmas. They were responsible for making the holiday run smoothly for wealthy landowners. They were allowed to take leave on December 26th and visit their families. The employers gave each servant a box containing gifts and bonuses. In addition, around the 800s' churches opened their alms boxes (boxes where people place monetary donations) and distributed the contents to poor."
But
http://www.snopes.com/holidays/christmas/boxing.asp says:
"The holiday's roots can be traced to Britain, where Boxing Day is also known as St. Stephen's Day. Reduced to the simplest essence, its origins are found in a long-ago practice of giving cash or durable goods to those of the lower classes. Gifts among equals were exchanged on or before Christmas Day, but beneficences to those less fortunate were bestowed the day after.
And that's about as much as anyone can definitively say about its origin because once you step beyond that point, it's straight into the quagmire of debated claims and dueling folklorists. Which, by the way, is what we're about to muddy our boots with."
When we acquired some English friends many years ago, we began to observe Boxing Day. Christmas is pretty much for family, and the next day we all gather at someone's house to decompress and enjoy friends.