Was it Really Canada Day?
Bash, 43 42 40 bytes

curl -L enwp.org/$@|grep -o Canada|wc -l


Uses curl, grep, and wc to count occurrences of "Canada" in specified webpage. Like the other answers, input is given in the format July_1. This is my first time posting on the Code Golf SE and I'm not quite familiar with all of the rules. Any feedback would be most welcome.

Didn't realize that output to STDERR is traditionally ignored. Thanks for the 3 bytes, Dennis!