Final answer:
The latest revision of AR 670-1 and DA PAM 670-1 was published in September 2020.
Step-by-step explanation:
The latest revision of AR 670-1, which is the United States Army Regulation concerning Army uniforms and appearance, was published on September 2020. As for DA PAM 670-1, which is the Department of Army Pamphlet that provides further guidance and clarification on AR 670-1, the latest revision was published in the same month and year.