Oops, it doesn't look like 'team plays the same opponent on the same day' is a national day..

Other days

kale

Kale Day

my little pony

My Little Pony Day

singles

Singles Day

prosecco

Prosecco Day

Me Day

cursing

Cursing Day

fiancee

Fiancee Day

brow

Brow Day

latina equal pay

Latina Equal Pay Day

gum

Gum Day