Canada Post probably DOES have policy regarding the date positions, but it does not mean it is always followed.
It is not just Canada, I have seen many date position variances from countries around the world.
Check these two cancels from Funafuti, Tuvalu.

The first is May 17, 2001 (with 01 inverted), the second is October 11, 2002
Normally the star (or rosette) is at the top, and year at the bottom
[BeeSee corrected dumb typo]