Im real sorry for asking this, I am sure its been asked a million times over. I did try a google search however didnt find what I was looking for within the ~15 minutes i looked. I plan to buy two Macbook Air's, one for me and one for my sister as a graduation present. I am waiting for the new models for myself, however she graduates this weekend and would like to give her the actual computer on that day. If I buy her a macbook air today how long do I have to return it / exchange it for the new model if it releases relatively soon?