EDC/Altoids Kit - Basically, 6 days. Assuming water to be purified can be found, whicj it should be in consideration of the parameters this kit is meant to function within. I look at this kit as an assist to "Bugging In" if I am ever away from my vehicle and need to get to it. This would get me there (to a more extensive kit) or substitute while improvising the important items for bugging in if my truck were to be destroyed or out of reach...highly unlikely. This kit would take me to the point where I would run out of a six day supply of water (longer if properly rationed) and suffered an end from dehydration. What's that...8 days, maybe. No food or methods of procurement are included in this kit.
The supplements in my truck are generally as follows...food, a more extensive kit for making it home from work or around town. I am rarely more than 30 miles from home, which I could cover in an easy three days, more likely two if adequatley nurished. Blah, blah, blah, the truck kit addition is there to make this doable in relative comfort. Additions include: MRE's, bottled H20 and more MP1 tabs, more firestarter, raingear, a change of clothes, tarp with guyline and stakes, sportsman's blanket, larger fixed blade, etc.

PSK - This is the kit I take to the woods with me while backpacking or rock climbing. Carried in a small lumbar pack at all times. I could last just about as long as I could without food with this kit although, it is designed to get me out of the woods to a road, mainly.

Unfortunately, there are few places that we can go in the SE where one is not more more than 10-15 miles from a road. I figure this kit would come into play if I were injured (a bad fall or maybe lightning), attacked (beasts two or four legged), or for whatever reason apart from my main pack...which would have to be very serious. Crawling or walking, I estimate that I could go 2-3 weeks. This is probably to the point of death from starvation. This kit is designed to provide fire, water, and food rations or methods of procurement for this amount of time. Bullion, fishing kit, snares, plus a good basic small survival kit.

BOB - Designed for a relatively comfortable 6 days in the woods for my wife and I. The decline after that would be in accordance with rationed food and declining supply of water, however with the size of this kit, procurement of water and food should be sustained for quite some time...weeks. We have a large river less than 200' from our building, and copious amounts of small mammals and fish from which to feed if neccessary. This is a large kit containing more substantial items such as a tent, sleeping bags, etc. It stays in a spare internal frame backpack in the corner of our bedroom.