If I needed to be completely unambiguous, I'd personally say some thing like "needs to be sent just before ...". Then again, often the ambiguity is irrelevant, despite which convention ruled it, if a bottle of milk explained "Best f used by August tenth", you couldn't get me to https://premiumlumbersforsale42739.humor-blog.com/35194675/everything-about-hardwood-lumber-for-sale