duration term

Hi

I'm looking for a while a way to change term of a content after an elapsed time.In my ming , it could be great to give the choice of duration to user.
So user create a content and choose a term to highlight the content on homepage for a choosing duration (he can choose a date or a duration).
After that this is my rules idea but need correction i think.

1-create a ruleset "Duration of content and term" with argument on content, date, term
2- create a rule into ruleset with actions:
=> Charge taxonomy term : the new one
=> Charge taxonomy term : the actual one