However, the event signifies the end of the Danish-ruled Kalmar Union, so in a sense it is a marking of Swedish independence, though the event occurred so long ago that it has not as strong a presence in the social consciousness as does, for example, the Norwegian Constitution Day, Syttende mai.[2] Although the national day is celebrated on 6 June, it is actually wrong due to the Julian calendar which was in use before 1582, when the Gregorian calendar was introduced, and which (before March 1700) was ten days behind the Gregorian calendar; the anniversary of the election of King Gustav Vasa should therefore be celebrated on 16 June rather than 6 June.