Modified Date button option added to form

We're using the RSDirectory to showcase species information on our website (native plants in the area). I noticed under Forms> Layouts > there are options to include "show publishing time" and "show expiry time". Is it possible that you could add a button there with "show modified time"? I know for classifieds, it wouldn't be a popular option, but we would love it so users know when the page was last modified and worked on.
Thank you so much!