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

Other days

cuddle up

Cuddle Up Day
eat what you want

Eat What You Want Day
bow tie

Bow Tie Day
lisp

Lisp Day
boba

Boba Day
ruby

Ruby Day
aloxolt

Aloxolt Day
coffee

Coffee Day
stud

Stud Day
singles

Singles Day