Oops, it doesn't look like 'take your flask to works day' is a national day..

Other days

nae nae

Nae Nae Day
kiss a ginger

Kiss A Ginger Day
bow tie

Bow Tie Day
pumpkin

Pumpkin Day
special education

Special Education Day
brow

Brow Day
hoodie

Hoodie Day
law

Law Day
gum

Gum Day
buddy

Buddy Day