The Celebration (Danish: Festen) is a 1998 Danish black comedy-drama film directed by Thomas Vinterberg and produced by Nimbus Film. It tells the story of a family gathering to celebrate their patriarch's 60th birthday, during which a family secret is revealed. Vinterberg's inspiration for the film, which he wrote with Mogens Rukov, was an interview broadcast by a Danish radio station, though the interview was later discovered to be a hoax. Festen was the first film of the Dogme 95 movement, which was created by Vinterberg and his fellow Danish director Lars von Trier.
https://en.wikipedia.org/wiki/The_Celebration