Hey, dope fiends! We just uploaded the Halloween update a bit early into the beta branch for testing. Officially it will hit the major release branch next Thursday.
You can opt into beta branch by going to the game's properties then selecting the betas tab then changing your branch. It will update the game and DLC, if applicable.
To enable Halloween mode you'll have to change your computer's clock/calendar to somewhere between midnight of October 28th to midnight of November 2nd. Or you can wait for the official release too.
There is new content, for both the game and DLC, as well as a bunch of system changes. If you find any bugs, please let us know about it!
The official release will be on Thursday October 27th.