Like with everything else that is DayZ, the Xbox One version of the game has seen a bit of a delay- it will not be hitting the console via the Xbox Preview Program (which is the Xbox equivalent of the Steam Early Access program) in 2015, as Microsoft originally announced at E3. Instead it seems to have slipped off into next year.
The developer confirmed this on Twitter, stating that they are at least as of right now more focused on bringing the PC version up to scratch; they also did promise, however, that a prototype of the console version should be up and running by early next year. Of course, with DayZ, deadlines are about as ephemeral as the weather, so who knows what will really happen.
If you really do want to play the game, you can do so right now on PC (though it’s still not completed there, either- it’s in Early Access). That, or really, there’s a whole host of clones that you could look into trying out.