Happy Canada Day!
a bit of history...
Prior to 1982, it was called Dominion Day.
Also as quoted on Wikipedia, quoting the Constitution Act and https://en.wikipedia.org/wiki/Colonial_Laws_Validity_Act_1865
"Section 52 of the Constitution Act, 1982 provides that the Constitution of Canada is the "supreme law of Canada", and any law inconsistent with it is of no force or effect", and
"Before the 1982 Act came into effect, the British North America Act, 1867 (now known as the Constitution Act, 1867) had been the supreme law of Canada. The supremacy of the 1867 Act had originally been established by virtue of s. 2 of the Colonial Laws Validity Act, a British Imperial statute declaring that no colonial law that violated an Imperial statute extending to a colony was valid. Since the British North America Act was an Imperial statute extending to Canada, any Canadian law violating the BNA Act was inoperative."
So we were not fully legally autonomous until 1982! Happy Canada Day!