years ago I thought boxing day was meant to symbolize:
1) a custom in some weird country where people were given the liberty to box (punch) whoever they wanted and not get arrested for it. 2) a chance to box (punch) the person who gave you the x'mas present if you thought the present was crappy.
but of course, the above isn't true.
I think the most common accepted explanation for boxing day today, is the opening of boxes (x'mas presents) on this day. (wow, so many deixis used here!)
well you're half right.
it's actually the tradition of giving gifts to the less fortunate, like clothes, food etc mainly via boxes to facilitate transportation. (has a long way back, you can check it up yourself)
I am damn sleepy it's 4am already and I'm damn lazy to type.