Dynamic Form Rules on Date Fields

I have a form with these three fields.  Date received, Term Length and Term Date.  I would like to set up rules so that the term date is calculated based on what Term Length is select.  So if 30 days is select form Term length then I would like the Term date to be 29 days from the Date Received.  I know this can be done with a formula field but was hoping it could be done on the form rules.  Is this possible?