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

Other days

brow

Brow Day
bubble bath

Bubble Bath Day
boy friend

Boy Friend Day
donate your hair

Donate Your Hair Day
carpenters

Carpenters Day
first love

First Love Day
tulip

Tulip Day
ormille

Ormille Day
latina equal pay

Latina Equal Pay Day
one

One Day