So, you get 7 days to live before a zombie horde comes. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. If you survive that, you get another 7 days. Surely you get the hint by now?