We could always move Veteran’s Day to September but then establish Armistice Day on 11 November, which is what the rest of the world calls that day. Net result would be one more federal holiday (just with some renaming).
Or, we could mess things up by leaving Labor Day and Veteran’s Day alone and adding “Armistice Day” in May. :)
Or the comment sections could just be merged together in the client view. Each thread of comments would belong to one (and only one) instance, so it shouldn’t be difficult to merge those lists together when presenting the aggregate view to the user.