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

Other days

polyamory

Polyamory Day
stud

Stud Day
lisp

Lisp Day
gallery

Gallery Day
latina equal pay

Latina Equal Pay Day
boba

Boba Day
law

Law Day
nail polish

Nail Polish Day
nae nae

Nae Nae Day
ruby

Ruby Day