Grundlovsdag

Constitution Day (Danish: Grundlovsdag) commemorates the anniversary of the signing of the Danish constitution of 1849 by King Frederik VII.

From 1660 until 1849 Denmark had been an absolute monarchy. The signing of the constitution established Denmark as a constitutional monarchy. 105 years ago on 5 June 1915 women were given the right to vote adding extra significance to the day. 

Traditions on this day include enjoying the early summer weather while listening to political speeches on the state of the government. While it is the closest to a national day, it isn't widely used to celebrate the constitution as seen in other countries.