I do not know how you would code it. But I use the qidentification resource for ID cards and they default to a 30 day expiration. All it does is print it on the card, but I am sure there would be a way you could export that variable and use it. You’d have to take a look at it.
I am certain I have seen vehicle registrations in CAD/MDT systems, but to have a skinny, standalone script would be cool. Let me know when you get to the beta testing phase, I love to test stuff. 
Disclaimer: I am not a programmer.