Oops, it doesn't look like 'kim sunggyu leg day' is a national day..

Other days

blanket fort

Blanket Fort Day
fiancee

Fiancee Day
boba

Boba Day
martini

Martini Day
self care

Self Care Day
ruby

Ruby Day
get funky

Get Funky Day
nae nae

Nae Nae Day
slime

Slime Day
camera

Camera Day