I think that boxing day was the day that workers changed jobs (i.e. management switched to the regular workers). I think this because of an old MASH episode where they decided to celebrate Boxing Day.
IIRC boxing day is the day after christmas, wherein the Victorian wealthy would give boxes of “gifts” (which I would imagine were more along the line of old clothes) to the servants. It’s celebrated in the UK and Canada, and I would imagine Down Under as well. So hopefully one of those folks will chime in with the full answer.
Some background:
England, and by extension, the British Empire, is widely recognized as having perfected the art of boxing as it is known today. Boxing was as popular in 19th century England as sex, perhaps even more so, since boxing (at the time) involved two men beating the crap out of one another, an activity which was widely understood to be good, clean fun (exercise and all that).
Alas, the British were so good at boxing, that the streets were littered with bodies every morning. In addition to the expense of removing the bodies, this also meant there was a rapidly diminishing pool of eager young foo… volunteers for the Army and Navy, both of which were deemed a necessary part of maintaining an empire. Something had to be done, and soon.
The general consensus was that although boxing was good, clean fun, it was also rather disorganized. For instance, while it was considered unsporting to club one’s opponent over the head with a cudgel, it wasn’t strictly forbidden, since there were no rules.
In December of 1867, the Marquis of Queensbury wrote a letter to the Times decrying the situation and proposing a set of rules. These rules were published on December 26th and immediately recieved widespread praise and acceptance.
The number of corpses found on the streets of London (and elsewhere) immediately dropped to a manageable level. The rest, as they say, is history.