Days Gone was first unveiled during E3 2016 and then went underground for around a year. The game, however resurfaced during Sony’s E3 2017 conference, but no information about the release date of the game was revealed.
The developers were also interviewed over the course of time but they managed to keep the release date a secret.
However, it seems that the release date of the game has finally been found out after a video which was deleted later in the official PlayStation channel leaked the date. The release date of the game is listed as December 29, 2017 in the video.
Here is a screen grab from the video:
The video showed every announced game and each of them came with a release window except Detroit Become Human, which was mentioned as ‘In development for PS4’. Days Gone was the only game which came with a particular release date, so this could easily be a mistake.
At this point we would want you to take this date as a rumor until the developer confirms anything. We might find out the potential release window of the game at the upcoming PSX 2017.