Bill, its a
Canada Post machine cancel. Can't quite make out the date struck over the stamp itself. All I can make out is 2005****. As well there may well be a flourescent ink machine bar code on the bottom, which the sorting office has been doing the last several years, on the back which usually has date at end.
And wow, that flag stamp almost looks like a reuse, as well the cover looks a bit grubby or dirty in image. And again when I look closer it appears the original label was removed and a shorter one put on. You can see shading differences at both sides of that new label.