How long would out processiong take if someone turned themselves in after being awol for more than 30 days.?

I have a friend who went awol three weeks ago to save his marriage after the NCO's and CO's told him get over it. He called the GI Hotline and was told that he would get a discharge if he turned himself back in after 30 days. Is this true and if so how long would it take for him to be outprocessed after turning themselves in. Need to know, really important.