I am aware of the dates, but, I do not accept them as being the law. I've had milk 30 days past and it was fine. Anything that contains any degree of vinegar will keep forever. Mayonnaise that is refrigerated will also last a very long time with no difference in taste or quality. So many refrigerate mustard and ketchup when it can stay out in a closed container at room temperature almost forever.
Meats I try to use no more then a few days past the best by date, but, you can tell a lot by just smelling it. If it is bad you will know immediately. The ones that actually make me angry are the ones that jumped on the "best by" date thing just to increase sales. Item like soda, beer and any canned product that is sealed and unopened has been known to last years and years and years.
My daughter came over to my place one time and I offered her a diet Coke. The first thing she asked me is what is the date on it, because she knows that I don't drink diet Coke. It was at least a year past the date. I convinced her to try it and I poured it into a glass. She took one sip and decided it was stale. (whatever that means) So then I told her that I had just bought some recently so I would throw away the "old" one and replace it with a new one. Yes, I was being sneaky. I only had that one 12 pack from a year before, but, I opened one up, put it in a glass and told her that this one should be a lot better. She tried it and agreed. That whole dated soda and beer thing is a total scam. Things in a completely sealed can, with no oxygen present and especially with today's preservatives are perfectly fine to consume and if the manufacturer tells you different, they just want you to throw away perfectly good stuff and run out and buy more from them.