Growing up, Boxing Day was spent visiting grandparents and aunts/uncles from one side of the family. As a kid, it was a second Christmas Day. Delicacies, family discussions, another little gift or two, hanging out with cousins, tobogganing down the big hill, and somebody else's toybox to rummage through. A perfect, happy day.
I was never one to chase Boxing Day sales, and long ago they morphed into Boxing Week sales anyway.