Oops, it doesn't look like 'kids flying day' is a national day..

Other days

coffee

Coffee Day
tulip

Tulip Day
china

China Day
tell a fairytale

Tell A Fairytale Day
hannah

Hannah Day
ride the wind

Ride The Wind Day
slime

Slime Day
lash

Lash Day
blanket fort

Blanket Fort Day
boba

Boba Day