The Day of the Finnish Flag is observed in Finland every year on the Saturday between June 20 and June 26, coinciding with the celebration of Midsummer Day by Finns and Swedes. This flag day has been celebrated annually since 1934 and symbolizes the light of Midsummer's night, during which the Finnish flag must be flown from public buildings from 6 p.m. on Midsummer's eve until 9 p.m. the following day. The design of the Finnish flag, featuring a blue Scandinavian cross on a white background, was officially adopted in 1978, although its origins date back to the late 19th century. The flag's ratio is 11:18, and it is commonly known as the Blue Cross Flag (Siniristilippu). The state flag includes a coat of arms at the center of the cross, while the military uses a swallow-tailed version, and the president's flag features a Cross of Liberty.