https://en.wikipedia.org/wiki/Russia_Day
WebRussia Day (Russian: День России, Den' Rossii) called Day of adoption of the declaration of state sovereignty of RSFSR (Russian: День принятия Декларации о государственном суверенитете РСФСР, Den' prinyatia Declaratsii o gosudarstvennom suvernitete RSFSR) before 2002, is the national holiday of the Russian Federation.