If I desired to be fully unambiguous, I'd personally say something like "have to be delivered just before ...". On the flip side, in some cases the ambiguity is irrelevant, regardless of which convention ruled it, if a bottle of milk reported "Best f used by August 10th", You https://arthuroaipw.blogscribble.com/36534009/the-smart-trick-of-lumber-for-sale-online-that-nobody-is-discussing