James Gunn’s announced Thursday that he started filming his now-retitled Superman epic on a day that ‘s pretty special to the Man of Steel.

“Overjoyed to be announcing the start of principal photography on SUPERMAN today, February 29, which just so happens to be – coincidentally and unplanned – Superman’s birthday,” Gunn wrote in a caption to a photo of what appears to be a close-up of his version of the Superman costume.

“When I finished the first draft of the script, I called the film ‘Superman: Legacy.’ By the time I locked the final draft, it was clear the title was SUPERMAN.” He added that the film would be “Making our way to you July 2025.”

Superman’s birthday was established when a comic reader sent in a letter to the editor wondering about Superman’s birthday and editor Mort Weisinger’s main assistant E. Nelson Bridwell answered in 1966’s World’s Finest Comics #164, with the date of February 29th.

Technically, there has been a film simply titled Superman before; the 1978 film featuring Christopher Reeve in the title role, however that film is often referred to as Superman: The Movie.

The film’s cast has been locked in for a while, David Corenswet will take on the dual role of Clark Kent and Superman, Rachel Brosnahan will play Lois Lane and Nicholas Hoult will play Lex Luthor. The rest of the cast includes Skyler Gisondo as Jimmy Olsen, Anthony Carrigan as Metamorpho, Edi Gathegi as Mister Terrific, Nathan Fillon as Guy Gardner, and Isabela Mercad as Hawkgirl.

Superman is set to open in theaters July 11th, 2025, from Warner Bros.