auto populate expiry and renewal date forcer

Summary:

Does anyone know a way how we can auto populate the expiry date and renewal date for certificates based on the issue date. But considering all different licenses and certificates would have different expiry and renewal dates.

This in the skills and qualifications page.  Previously I would have thought of doing this using autocomplete rules and adding logic there. But that feature is no longer available and now we have to use validation rules in VB studio . Can we use Autocomplete rules if the Business Object is supported (or the same in VB, as I think the Autocomplete rules are now part of VB). Is this correct understanding? Has anyone done this for any of the clients.