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

Other days

gum

Gum Day
kiss a brunette

Kiss A Brunette Day
nae nae

Nae Nae Day
nail polish

Nail Polish Day
pick me

Pick Me Day
ruby

Ruby Day
pumpkin

Pumpkin Day
unicorn

Unicorn Day
carpenters

Carpenters Day
hoodie

Hoodie Day