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

Other days

kale

Kale Day
offer

Offer Day
slime

Slime Day
girl friend

Girl Friend Day
ormille

Ormille Day
cursing

Cursing Day
stud

Stud Day
kiss a ginger

Kiss A Ginger Day
donate your hair

Donate Your Hair Day
bonang

Bonang Day