How long does it take a nose piercing to stay open?

I'm getting a nose pericing, not a ring just a diamond small, so there's only one hole. My school does not allow guys to have pericings so I will have to where those little bandages over it for zits. But I don't want to have to do that the whole year so how long do I have to where the pericing to where I don't have to where it at school and can just put it in after school?