I have spent the past decade in America and many of my friends do not know what December 26th, Boxing Day, is all about. There are essentially two traditions that have merged to give Britain and many of its old dominions this day of celebration. The first is that, dating back all the way to Medieval times, alms boxes were often left out for people to donate to the poor. On the 26th December the contents were then delivered or given away. The second is that servants and tradesmen were often required to work during Christmas day and were therefore given their own day of celebration. This became Boxing Day. The day their boxes were opened.
Growing up my memories of this day were always very similar. Christmas Day was spent either at my parents house or at my grandparents house. Boxing day was then celebrated at whichever place we had not yet visited. While Christmas saw the traditional Christmas meal, Boxing day was left overs and other delicious foods that were supplied in a buffet style by either my parents or my grandparents. Mince pies, pigs in a blanket, cakes [more Christmas Cake particularly], small sandwiches with various fillings available and so on.
This has also been a big sports day in the U.K. Similar to how Americans what their 'football' on Thanksgiving, the Brits love their 'football' on Boxing Day. It's the start of a rather hectic period of sports where one of the big teams can often put themselves ahead in the English Premier League. If we never went to watch our local team live then we rarely saw a game on T.V. but I do remember watching a show on BBC1 called "Grandstand". This was a popular sports show and the latest scores would always be flashed up on the television. Nanna would also often turn the radio on. Our local team, Grimsby Town, was not particularly famous but the local radio would always broadcast live from the stadium.
We would spend the day playing games, showing off the presents from the day before and I would often read a lot. Usually at Christmas I would receive a book of some kind and Boxing Day would find me marking time by devouring it as quickly as possible. The day was also interspersed with movie watching. Christmas movies and one or two former big blockbusters would be on T.V.
Since moving to America it has been little different. I still manage to make it to England periodically for Christmas but when I'm not then Boxing Day is no national Holiday. It's just December 26th, the day many Americans return the gifts they didn't like. I follow the football scores on the internet but rarely watch the Boxing Day games. I still eat left overs with whichever family members are visiting and I still read rigorously. I've always had that day off work so the fact that it isn't a national holiday has never factored into my enjoyment of it.