Proclamation Day of the Republic of Latvia

Proclamation Day of the Republic of Latvia is celebrated annually on 18 November. It marks the anniversary of the Proclamation of Independence of Latvia by the People's Council of Latvia in 1918.

Observances
Various public events take place all over the country, including concerts and fireworks. Torchlight processions held by various organizations have been part of Proclamation Day celebrations and Lāčplēsis Day celebrations since the 1920s.The largest torchlight procession organized by the National Alliance takes place in the capital city Riga and attracts several thousand participants every year. Its route through the streets of the city centre traditionally starts at the monument of Kārlis Ulmanis, the first prime minister of Latvia, and ends at the Freedom Monument.Another tradition with a long history is the Latvian National Armed Forces parade, which nowadays is held at 11 November Embankment in Riga.A popular modern tradition established in 2009, is for people all over the world to sing the Latvian national anthem Dievs, svētī Latviju! at the same time (21:00 EET).
en.wikipedia.org

https://en.wikipedia.org/wiki/Proclamation_Day_of_the_Republic_of_Latvia