How long should I keep something in the freezer to chill it?
One could probably figure it out, but imagine the variables:  (a) temperature of the liquid before entering the freezer, (b) volume of liquid, (c) shape of container, (d) temperature of freezer, (e) air circulation in freezer, (f) desired final temperature...I would eye-ball it.  Give it 30 minutes, check, and proceed one way or the other.