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

Other days

azonto is acceptable

Azonto Is Acceptable Day
artists

Artists Day
blanket fort

Blanket Fort Day
brow

Brow Day
one

One Day
cat girl

Cat Girl Day
lash

Lash Day
martini

Martini Day
latina equal pay

Latina Equal Pay Day
hoodie

Hoodie Day