Interviewed late August. I feel like everyone says this, but relax (seriously). The whole day is surprisingly laid back and conversational. We met in a conference room, met with some admissions people, and then the interviewers walked into the room and paired up with the applicants. The questions were pretty standard, just discussing your research, shadowing, background, etc. One question I wasn't prepared for was my thoughts on how I would address legislators regarding healthcare, ACA, etc. They weren't looking for a right or wrong answer, just wanted me to have a logical opinion on the matter. I also had an interview ask me to tell them a joke at the end of the interview (I froze, not even sure I can remember what joke I came up with). So you might have a joke in your back pocket in case that happens to you
Don't sweat it.