The day was adopted by the Riksdag as the National Day of Sweden in the 1980s. This was concurrent with a tradition established in the 1920s of celebrating the Day of the Swedish flag, on June 6. The main reason for picking that date had been the election of Gustav Vasa as King of Sweden in 1523, who is seen to have established the modern Sweden. The Constitution of 1809 and Instrument of Government of 1974 were also been promlugated on this date.
The National Day is not yet an official holiday, but the political parties in Parliament has announced a consensus intention to make it a full holiday by 2005. The intention is to achieve this by canceling one of the current official holidays, most likely Whitmonday. The day is however an official flag day.