I have hung deer in my cooler for 7-10days (client request) & I set my cooler to maintain a internal meat temp at 34-37 degrees. A normal fridge will be closer to 40 degrees I'd guess, so I'd say a week max. Like mentioned monitor it by smell, however don't open to much as you want the cool air in not out.
For the record I don't really believe in aging vension longer then the relax period(rigor: sugar to lactic and back to sugar), which is 24hr's.