Ben Affleck took to Instagram to offer a late posting by reg-ramming the Happy Batman Day Batman v Superman post.
Joseph Gordon Levitt, who played Robin for Christopher Nolan in The Dark Knight Rises, also joined in on the Batman Day festivities.
Ben Affleck returns as Batman in November's Justice League.
How about Joseph Gordon-Levitt as Nightwing?
Justice League has a November 17, 2017 release directed by Zack Snyder, with the story by Chris Terrio and Zack Snyder, the screenplay by Chris Terrio and Joss Whedon, and stars Ben Affleck as Batman, Henry Cavill as Superman, Gal Gadot as Wonder Woman, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, J.K. Simmons as Commissioner Gordon and Willem Dafoe an Atlantean, Nuidis Vulko.
Fueled by his restored faith in humanity and inspired by Superman’s selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of metahumans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes—Batman, Wonder Woman, Aquaman, Cyborg and The Flash—it may already be too late to save the planet from an assault of catastrophic proportions.