This cast gives our guidance on when to arrive for an interview.
It turns out that there is a perfect time to arrive before an interview. Too early, and the interviewer is not ready and feels flustered and hurried by your arrival. Too close to your interview time, they're not sure whether you're coming or not, and start to worry. After your interview time, and there are two problems - one, you've started your interview with a negative, and two, you have a shorter time to get yourself out of that hole.
Does it really matter? Yes. The idea is that you want the interviewer to like you. The way you do that is to make their life easier. The way you do that is to be on time. Being on time means not too early and not too late.
What is the perfect time? 8 minutes before your interview.