Although you have to be there at around 10:30, the day does not start until about 11:00. You start with some briefings about the school and financial aid, followed by a pep-talk from a faculty and MS IV. After the talks, we ate lunch and then took a brief tour (about an hour). Due to time constraints, the tour was rather short and skipped a lot of areas I was interested in.
As for the interview, I had a fantastic experience at OSU! I was very impressed that they read my application materials and had paired me with an interviewer who the head of the corresponding department!! Immediately had a connection and a common interest, which made the interview that much less stressful. Since I was first on the interview list, my day was over before 3:00. Oh, they also make an admission decision that day and you find out 3-4 weeks later - might know by X-Mas! Wahoo!!