No idea. But with that many to spare, you could just start up a small flat or pot of them, and see if they germinate or not. If they do, there you go. If not, go to the store, buy a new packet, and throw out the old ones.
I use plastic containers that we get our Chinese take-out in. Poke some holes in the bottom, fill with seed starting mix or Jiffy pellets, and throw some seeds in there. Snap on the lid and keep an eye on it. An even easier experiment would be just to put some seeds in between two damp paper towels. Keep them on the counter, keep moist and within a week you'll know.
Whereabouts do you live? It might not be too early to start up some marigolds for bedding plants now anyway.
Could you put in your location, (city and state or country) in your personal profile, please? It really helps others to help you, if we know where you are.
