Any call that originates before the specified "free time" will be charged for the entire length of the call. It would be best to tell the caller to hang up and call back.
On your bill, it would be listed as two calls... one that was 2 minutes from 8:59 - 9:00 and then another that started at 9:01. Also, remember that when making a phone call, if you pick up on the phone and talk for 3 seconds it still counts as a full minute call, so in this inccident, you'd only save 1 minute
Nights start at 9:01pm and end at 5:59am.