Hollywood gears up for ‘Dunesday’ as Robert Downey Jr. and Timothée Chalamet confirm a December 18, 2026 box-office clash between ‘Avengers: Doomsday’ and ‘Dune: Part 3’. While ‘Doomsday’ is a strong contender, ‘Dune’ faces an uphill battle. Both films will vie for premium formats, raising questions about profitability.