The Icelandic National Day.

The 17th of June is the Icelandic National Day.
Icelandic National Day (Icelandic: Þjóðhátíðardagurinn) is an annual holiday in Iceland which commemorates the foundation of The Republic of Iceland on 17 June 1944 and its independence from Danish rule. The date was chosen to coincide with the birthday of Jón Sigurðsson, a major figure of Icelandic culture and the leader of the 19th century Icelandic independence movement. (Wikipedia)