Hi Ciardeme,
I received an interview invitation a few weeks after my application was complete, and I received a decision letter exactly one month after my interview.
The interview day is very relaxed; they make a genuine and obvious effort to put you at ease! One student interview, followed by an interview with a faculty member/ administrator. At the very beginning of the day, the Dean of Admissions sits with the entire group for a chat, to become acquainted, and he touches base with each applicant individually at the end of the day.