Usually you want 24-48 hours for a starter, but at least you're making a starter. Considering it is 2 months old, I'd go for the 48 hours, but if time isn't on your side (have to work monday?), you'd be ok. Be ready for a longer than usual lag time between pitching and seeing activitiy. Also, oxygenate the heck out of the beer before you pitch.
Bottled: Oatmeal Porter, Double Chocolate Chipotle Porter
Kegged: IPA, Red Rye