I seriously doubt it matters. I don't think it's like ice skating or something and the judges are saving the good scores for the end lol. Most interviews are conducted with the interviewer using a standardized score sheet so that the interviewees can be easily ranked.
If it is a school with rolling admissions however, I would think you would be more likely to get in if you interview in say October or November, than say February or March...depends on the method the schools use for filling their class.
If it is a school without rolling admissions I don't see why it would matter at all. These schools generally interview all candidates before ranking everyone and sending out acceptances.
