Originally posted by: Captante
As long as it hasn't turned sour you would be fine drinking it right out of the carton (although I wouldn't) & even if it has turned sour it won't make you sick cooking with it provided it maintains 180f or higher for 10 minutes which will kill off any harmful bacteria... most likely it'll taste foul though.
The amount of time milk will keep depends mainly on the tempeture its stored at ... the colder it is the longer it will last & 2 weeks beyond the expiration date isn't unheard of if its been kept consistantly cold since its been packaged although it is about the limit.
Edit: Cooking using sour milk