Complex sentence: The real ship was at sea 567 days, the product of 7x9x9, which has been taken as a confirmation of the allusion, which if correct, confirms that the play could not have been written any earlier than July 1606.
Split into simpler sentences: The real ship was at sea 567 days, the product of 7x9x9, which has been taken as a confirmation of the allusion. If this theory is correct, the play could not have been written any earlier than July 1606.