Suggestion for comment editing

I think comment editing should have a time limit, for example you comment someones page, and you have five minutes to edit the comment, so they cant change everything they said to something completly different, would make confusion, and members could cause trouble this way, so my thought is this

On the edit area have a limit that you can adjust via admin panel like

EDIT (5 minutes)

so they can proof read for typos or whatever