What is the shelf life of oregano anyways?

Last night, for one reason or another, the "basket-o-spices" was out on the table, and I came across something a little out of place:



















Ground oregano? That's the "out of place" something he was talking about? No, no folks. Ground oregano, especially the kind that comes in such a generic container, is not out of place in a "basket-o-spices". What was out of place is what it said on the lid:



















Wow! On June 21th, 1992, this oregano was unfit to sell, yet we happen to have some in our house! No wonder everyone gets sick around here, we all have oregano poisoning!

Oh wait, does that say "06-20-92 B"? Hmm, well, I guess I'll go put it back...