I don't think I've ever heard them called that....expiry dates.
Where I come from it's "expiration dates".

I think it's a regional thing. I use "expiry date" because I like the sound of it when giving my CC info over the phone. Nobody has ever asked for a clarification or been confused by it. I live on the Left Coast of the central portion of the North American continent.

Ceci n'est pas un seing.