【How-to】When is the post office closed

Does USPS Deliver By 8 PM? Mail can arrive as late as 8 p.m., including your First-Class (or “regular”) mail, but especially packages, if they aren’t delivered with your First-Class packages. … Those late deliveries are out of the norm, however, and regular 8 p.m. deliveries might merit a call to your local post office.