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

Other days

boba

Boba Day
lisp

Lisp Day
ride the wind

Ride The Wind Day
lumpy rug

Lumpy Rug Day
bubble bath

Bubble Bath Day
book

Book Day
first love

First Love Day
ormille

Ormille Day
latina equal pay

Latina Equal Pay Day
ruby

Ruby Day