What is Crown Prince Haakon day Holiday ?

Haakon, Crown Prince of Norway (Norwegian pronunciation: [ˈˈhoː.kʊn]; born 20 July 1973), with the full name Haakon Magnus, is the heir apparent to the throne of Norway and the son of the current King, Harald V. He is a member of the House of Schleswig-Holstein-Sonderburg-Glücksburg, which is a branch of the House of Oldenburg. In accordance with Norway's agnatic primogeniture succession, he became crown prince when his father ascended to the throne in 1991. He has an older sister, Princess Märtha Louise. Should he ascend as expected, he will be known as Haakon VIII.