If I needed to be totally unambiguous, I'd say one thing like "should be delivered prior to ...". Conversely, from time to time the ambiguity is irrelevant, irrespective of which Conference ruled it, if a bottle of milk reported "Best f used by August tenth", you couldn't get me https://israelnxfms.thebindingwiki.com/8357844/5_simple_statements_about_where_to_buy_lumber_explained