I understand that it celebrates the creation of a unified Canada under the British Empire. However, I was under the impression that the independence of Canada is something that was always rather murky and there are no firm dates for any independence.
That being said, the rest of my family is going to visit your fine country tomorrow, although I'm rather stuck at home. My wife and kid are visiting my BIL near Seattle, and they plan on crossing the border for a few days. My wife and kid have been there (with me) last year, but this is the first time my FIL/MIL will have visited Canada. Do the celebrations last? It's actually a year to the day that we visited last year, and we just missed the crowds for the WWC final.