I'm at day 511. I don't really see any point to continue. There isn't enough content in the game, and what is there is basically just a track for us, the player, to go down (i.e. go ahead and fight the zombies and lose before day 50, or run run run & pray).
I don't get the point of even HAVING armor and weapon upgrades in the game., as it's pretty clear that fighting was not the focus. I don't know...just too repetitive/Not enough, but still addicting.