Orthodox Book Day is observed in Russia every March 14, celebrating the significant contribution of publishing to the spiritual development of Orthodox Christians. Established by Patriarch Kirill in 2009, the holiday commemorates the publication of the Acts and Epistles of the Apostles, the first Russian printed book with a known date, completed in March 1564 by Ivan Fyodorov and Pyotr Mstislavets. The first official celebration took place in 2010, coordinated by the Publishing Council of the Russian Orthodox Church. Typical customs include book exhibitions, public readings of spiritual literature, and meetings with Orthodox writers at libraries and Sunday schools. In Moscow, the Patriarch and city officials often participate in events with schoolchildren, distributing free spiritual books. The day emphasizes the importance of Orthodox literature for the intellectual and moral growth of the Russian people, particularly the youth.