Mine expires March 23. I sent my application on the 149th day (October 24). I sent it to Dallas, got my Bio App today (Nov 14). The appointment is for Nov 23 and the letter came from the Nebraska Service Center. Was planning to do a walk in if the appointment happened to be on... let's say mid December. But if it's just the 23rd, I don't want to mess around with it. Gotta drive 200 miles to make my app (hate to sound snobby, out on holiday) and I'm not about to reschedule, as I said, I don't want to mess with it. Very best of luck... and patience.