Developer "will not compromise the project for the short-term gain" of shipping this year.
DayZ creator Dean 'Rocket' Hall has warned that the standalone release of his hit survival horror mod could slip into 2013.
"We are still working towards a target for an initial foundation before the end of the year," Hall said on the official DayZ development blog.
"But we will slip this date if needed, we will not compromise the project for the short-term gain of meeting this date."
Any reason for the delay "would be publicly discussed," Hall says, "and would most likely represent a failure personally on my part to plan correctly.
"We will be assessing the results of our major architectural changes at the end of next week, and reporting the results to everyone when we have assessed that."
Nonetheless, development of the standalone version appears to be going strong, with a Steam launch for the foundation release still scheduled for this year.
According to Hall, much of the "under the hood" tech has been completely rewritten, with significant "architectural changes" made to the game engine and model.
"We are moving to the server-client MMO architecture model," Hall added. "We are making weapons and items 'entities', meaning we can support customization and variables assigned against items.
"As discussed previously, this is a massive departure from the previous engine. In many ways, once this phase is completed - one could effectively say that DayZ is running on a new version of the engine. While the graphics may look the same (for now), under the hood so much is being completely rewritten."
As well as launching on PC, the standalone version of DayZ may also see a release on consoles further down the line.
Earlier this year, publisher Bohemia told VideoGamer.com that it would "be stupid not to" consider DayZ for a console release.
Source: DayZ Tumblr | Dev Report: November 2012