This is a perfect add-on for every forum! Very often, especially for an upcoming event, a user may need access to EDIT their own thread past the default time limit you've declared in XF. So you can now easily extend that expired timeframe for just a single post at a time.
My only problem with this add-on was re-locating it after I read it's description a month or so ago. I kept searching for 'Edit Time Limit', or 'Edit Expiration' and could not turn anything up. LUCKILY, I finally tripped across it again! If you're reading this, save yourself the effort of finding it again and just install it now.