There is no doubt that historically Christianity has had a major influence on Canada's history however and remains, even nominally, a factor in the lives of numerous people however we are not a theocracy of any sort and our laws are free of religious effect. 

Non Christian religions and other cultures often have their own calendars. The fact that the world has settled on using the current one is an act of convenience,  not a sign of any religious significance. After all, the allegedly Christian holidays you list are hardly definitive given how the timing of the new year, Christmas, and Easter have all been subject to human whim over the centuries.