National Day of Sweden (Swedish: Sveriges nationaldag) is a national holiday observed in Sweden on 6 June every year.
Prior to 1983, the day was celebrated as the Swedish Flag Day (Swedish: Svenska flaggans dag).
At that time, the day was renamed the Swedish national day by the Riksdag.
"Du gamla, du fria", "Thou ancient, Thou free") is the de facto national anthem of Sweden. It was originally named "Sång till Norden", "Song to the North"), and the first words of its lyrics have become adopted as the title in the interim.