However, though both houses must be notified on the same day, notice to the House of Commons while it is not in session may be given by way of publishing a special issue of the Journals of the House of Commons, whereas the Senate must be sitting and the governor general's letter read aloud by the speaker.
How can the House of Commons be notified of assent if it is not in session?
publishing a special issue of the Journals of the House of Commons