If it says 670 days left on the InmateAid inmate profile, that is the adjusted release date with the good time already figured in. Sounds like a 2018 release date.
https://www.inmateaid.com/ask-the-inmate/on-my-friends-info-it-says-he-has-670-days-left-will-he-do-them#answer
Accepted Answer Date Created: August 10,2016