Doomsday’ and ‘Dune 3’s Opening Day Is Now Dunesday

These days it can sometimes feel like movie theaters go weeks and weeks between major releases. But arguably the two biggest movies of 2026 — Avengers: Doomsday and Dune: Part Three — both open on the same day this year, December 18.

Movie theaters are sure to be thrilled (and packed). There hasn’t been that kind of a day in multiplexes since July 21, 2023, the day that both Oppenheimer and Barbie both opened in theaters. Movie lovers dubbed the dual releases “Barbenheimer.” The hype around the competition helped make both movies massive hits.

Marvel star Robert Downey Jr. was in Oppenheimer so he is surely aware of that. Which might explain why he and Dune star just offered up their own suggestion for a “Barbenheimer”-style nickname for December 18: “Dunesday.”

You can watch the stars offer the suggestion at a Marty Supreme screening in the video below:

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I gotta say … it’s a pretty catchy name.

Doomsday is the first Avengers movie since 2019, and Downey’s first return to the Marvel Cinematic Universe since then as well. Dune: Part Three is director Denis Villeneuve’s adaptation of the first Dune sequel novel, Dune Messiah, and it will supposedly conclude his trilogy of films based on the popular sci-fi books.

Both movies should be huge hits. But unlike Oppenheimer and Barbie, which presumably appealed to very different audiences, Dune: Part Three and Avengers: Doomsday would seemly target the same core group — namely huge, titanically obsessive nerds, dorks, and geeks.

Will the excitement around both lift up both movies’ fortunes? I guess we‘ll see. The fact that the competing stars are now hyping the films collectively with a nickname suggests Marvel and Warner Bros. do not plan on shifting either film’s release off that key date.

Avengers: Doomsday and Dune: Part 3 both open in theaters on December 18. On Dunesday? Are we doing this?