I think that the 3 day idea should be considered a starting point. I believe that the Red Cross now says that you should start at 3 days and then build up to week. 3 days is also a good way to get the PHRASECENSOREDPOSTERSHOULDKNOWBETTER. ( that term fits so well, I had to steal it) involved. Remember the un-prepared are not only un-prepared, they can be clueless as well. We keep our preperations low key and have planned for those who are welcome and we some set aside for anyone else that show up on the doorstep.