Social Media Study: Best times to post to Twitter, Facebook, and Tumblr Twitter is good for afternoons; Tumblr is best after dark. By Michael SebastianMay 14, 2012 SHARE To read the full story, log in. Become a Ragan Insider member to read this article and all other archived content. Sign up today Already a member? Log in here. Learn more about Ragan Insider.