How to use the find my iphone app to find an offline device if it's been longer than 24 hours?

Yeah, like the question said I need a little help finding my iphone. Our family went on a vacation to visit family in another state, and the day we left, I lost my phone but couldn't find it because it happened to be powered off. So I left for a Week with my phone still unfound, and when I got back I could not seem to check where it was last located. When I looked at the apple help site it says it can only show for up to 24 hours. This seems really retarded of Apple to only make it 24 hours, someone please help. This way I can rule out if it was last at our home, or like the airport or Mcdonalds or something.

You can't if its off, but you can prevent anyone from ever turning it on. Make sure you activate lost mode and put a msg on it saying "Lost iphone, email me at xxxx" etc. Call your carrier and report it also.