My inmate is in Safford State Prison Graham Unit and he already has a release date. Is there any way he could get anymore time off, maybe working (which he already does), good behavior or anything at all.

Good time is normally calculated into the release date. An inmate can only have good time taken away and therefore add time to the release date. In state prison, there are some programs where working harder labor, like long kitchen detail hours give more good time. Have your inmate ask his counselor or unit manager about programs that exist which might carve off some more time.