Depending on how much damage they are correcting I would say about 6 hours if fair just for the exterior. You have a new car so polishing may not yet be necessary. The best thing you can do is a buy a good quality wash mitt to avoid doing massive damage every time you wash. Go to Autopia and get your PhD in automotive detailing.
I prefer the natural wool mitt and it gives me no trouble on my current dark blue vehicle.
http://www.autopia-carcare.com/vk-103.html