Because Canada was founded on Christianity.
Islamic countries that are based on Islam have Islamic holidays, etc.
What is really worrisome is having to change our ways to meet a religion that does not always appear to have tolerance.  Unfortunately, I cannot say anything about misogyny associated with being forced by a religion to cover one's head or about gays being killed in the name of this religion as it offends people.  And because it does, I shall refrain.