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

Other days

my little pony

My Little Pony Day
lost sock memorial

Lost Sock Memorial Day
kale

Kale Day
law

Law Day
nae nae

Nae Nae Day
one

One Day
offer

Offer Day
book

Book Day
donate your hair

Donate Your Hair Day
gum

Gum Day