As Exhibitor Relations confirm below, Warner Bros. have dated two big releases for September 27, 2019, and February 7, 2020. We've been waiting for an official release date for Ben Affleck's solo Batman movie (currently dubbed "The Batman") for a while now, and there's certainly a decent chance it's the 2019 movie - but of course, there are many other possibilities.
In fact, it's not necessarily a given that either of the films will be DC projects, as WB also has the likes of the Harry Potter spinoffs, Kong: Skull island, and more. That said, if the studio is planning to go full steam ahead with the burgeoning DCEU, it seems likely that at least one of these spots will be filled by a superhero flick.
We'll update if and when we find out any more, but for now let us know which movies you think will wind up being released on these dates.