Working on my ifr training and have an instrument question.

Two 4500's and a 430W.

the 430w is the certified ifr unit so I have to update the nav info on a monthly cycle for those months I'm IFR.

As to the approach plate database through AFS, is this also a monthly database that has to be updated every month?

Alternatively, as long as I have current approach plates somewhere in the plane, can I use an expired AFS approach plate for geo-referenced guidance?

So, two databases every month? Or some work around?

Or am I totatlly misunderstanding? If so, a little guidance (small pun) would be appreciated.

Thanks,
Tom Hanaway