Oops, it doesn't look like 'office some day' is a national day..

Other days

nae nae

Nae Nae Day
hannah

Hannah Day
gum

Gum Day
slime

Slime Day
boba

Boba Day
blanket fort

Blanket Fort Day
buddy

Buddy Day
ormille

Ormille Day
get funky

Get Funky Day
martini

Martini Day