Body work and paint

I have to question about this. I was watching a car program last night and they said that once a car leaves the metal shop and goes to body work for block sanding and paint that it can take up to 8 months. Now the way I understood it is all the sheet metal work is complete, isn't 8 months to long? I know that prepping for paint isn't easy as they make sure that there's no waves or other imperfections