Oops, it doesn't look like 'make up a fucking day' is a national day..

Other days

pick me

Pick Me Day
nae nae

Nae Nae Day
slime

Slime Day
offer

Offer Day
blanket fort

Blanket Fort Day
believe

Believe Day
ruby

Ruby Day
bubble bath

Bubble Bath Day
boba

Boba Day
ormille

Ormille Day