Sybirak’s Day is observed in Poland every September 17, commemorating the Soviet invasion of Poland in 1939 and the subsequent deportation of over 300,000 Polish citizens to Siberia. This annual observance was established by a resolution of the Polish parliament, Sejm, in 1998. The day honors the memory of those deported, many of whom were sent in four mass waves, as the Soviet Union did not recognize them as Polish citizens. The term "sybiraks" refers to Poles exiled to Siberia, a practice that dates back to the 18th century. Although Sybirak’s Day is not a state holiday and typically falls on a working day, it is marked by special ceremonies across the country to remember the victims of this tragic chapter in Polish history.