Ben Croll Ever since his first trip to Russia in the late 1990s, filmmaker Antoine Cattin has always been tickled by his adopted country’s record number of national celebrations. Born in Switzerland and based in Saint Petersburg for the past two decades, Cattin has paid an up-close and rather bemused view to the parade of party days where people take to the streets, fireworks light up the sky, and the government sends often contradictory messages about national heritage and civic pride.With “Holidays,” which is set over the course of seven of such public fêtes, and which will world premiere at CPH: DOX on March 29, Cattin both filmed and offered cameras to a Kazakh migrant, an aging public administrator, a xenophobic young activist, and a thrill-seeking urban explorer, making the film’s four characters both subjects and guides on a kaleidoscopic tour of modern Russia.