DayZ is a mod for the 2009 video game ARMA 2DayZ (video game), a standalone game derived from the aforementioned modDayz (Nissan), a rebadged version of the Mitsubishi eK car.
See also: DayZ (video game), DayZ (mod), Dean Hall (game designer), Bohemia Interactive, Better Dayz, and Mitsubishi eK.