I was given a cyro pack of ribs for my birthday, ok, so that may be a little strange, but he loves my Q! Anyway, I didn't get a chance to cook them for a couple of weeks. I opened them 3 days after the sell by date, and they smelled bad and had a dark spot on one rack. I trashed them and called the meat manager at Sams club. He told me to bring him the price sticker off the pack and he would make them up. When I talked to him later he told me that most pork would be good for about 1 week after the sell by date, but don't take any chances.
Ed