How long does it take to get discharged from the air force?

im backing out of the air force and i guess they want a meeting with me to try and get me to stay in, im gunna go into the army so i want tot get this over with ASAP. so i can get in the army. And no need to tell me about how people might not take me cause i backed out of one branch, cause the army recruiter is a friend of mine. OH and im in the DEP im not actually in yet