Hello, Can someone please tell me what the Kongelig Balletskoledag is?

Rosie, I'm translating from the Danish ticket agency blurb below:

"Ballet Stars of Tomorrow. Something entirely new: the Royal Theater's ballet schools in Copenhagen,
Holstebro and Odense get their own show on the main stage of the Royal Theatre. The 125 students between 7 and 16 will show excerpts from Napoli's third act and Graduation Ball, steps from class and new choreography by Louise Midjord, Ann Crosset, Esther Lee Wilkinson and Ann Kolvig. Anne Marie Vessel Schlüter is MC and will delight us with ancedotes about the young dancers."