Oops, it doesn't look like 'soccer team arrived in new york on a day' is a national day..

Other days

lash

Lash Day
bow tie

Bow Tie Day
promposal

Promposal Day
lisp

Lisp Day
first love

First Love Day
brow

Brow Day
slime

Slime Day
one

One Day
boba

Boba Day
carpenters

Carpenters Day