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

Other days

boba

Boba Day
special education

Special Education Day
bounce

Bounce Day
lash

Lash Day
nae nae

Nae Nae Day
polyamory

Polyamory Day
nail polish

Nail Polish Day
comfy

Comfy Day
one

One Day
singles

Singles Day