3 days for a natural disaster is probably enough if you are careful and wise with its use. But under the current situation , a very real food shortage is coming especially in the west, if your in the USA , I believe you better brace yourself, but all of us do no matter where we live, it is said there is only enough food to feed the planet for 90 days...thus giving time for new growth , and with what has happened to the farms, cattle and food supply companies lately , I doubt 3 months will be enough...if you have this amount get ready to apportion it so as to make it last longer if you cannot afford to purchase more.