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

Other days

singles

Singles Day
lisp

Lisp Day
prosecco

Prosecco Day
carpenters

Carpenters Day
offer

Offer Day
ruby

Ruby Day
cursing

Cursing Day
promposal

Promposal Day
stud

Stud Day
ponytail

Ponytail Day