The 29th day
60 days
If you're referring to call of duty, yes you need to complete campaign to unlock zombies.
Complete Solo Campaign on any Difficultly
You already have it or you can buy a map pack. (Also, I think you have to complete the story mode.)
To play Nazi Zombies you must have Call of Duty: World at War & have either an Xbox 360, PC or a PlayStation 3 (it's not in the Wii version of the game). To unlock it you have to complete campaign/story mode or you can unlock it playing online.
U can unlock guns by killing a certain amount of zombies or doing certain achievents
You have to beat the game and then its says you have unlocked to unlock it
You will unlock the Gatling by the end of Day 13.
To unlock Nazis zombies you have to beat the game first.
No
On Xbox 360, PlayStation 3 and PC versions, you have to complete the story in order to unlock the Zombies mode. But on PlayStation 2 and Wii versions, they did not add the zombies mode to those consoles.
Their isn;t Nazi Zombies for Cod4 but for Cod5 yes, and their isn;t a unlock cheat. Just beat the campaign.