Formerly Dominion day, celebrated on the anniversary of the British North America Act (Now the Constitution Act) which when implemented in 1867 united Canada as a country. (New Brunswick, Nova Scotia, Ontario, and Quebec originally.)
Unlike the United States' national day 'Independence Day', only the formation of the country is celebrated. Being as Canada was not a fully independent state until the Canada act of 1982.
As a child I had very little understanding of the history behind the celebration and was greatly frustrated by the (to my mind at least) nonsensical proceedings. Though as I learn the history and get a true sense of what is actually being celebrated, I begin to develop warmer feelings towards the practice. After all it is not simply an anniversary that is being held, but a remembrance of the beginnings of a society that connects and serves (though poorly at times) approximately 33 million people in a way that a disconnected populace would be hard pressed to.
My city has an annual parade, as well as fireworks the night before. I myself was in the parade last year. My sister is in the Parade today, perhaps if I can find a picture in the city website I will link to it.
Happy Canada Day,
British North America Act 1867
Canada Act 1982
Grande Prairie 08 parade