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

Other days

unicorn

Unicorn Day
prosecco

Prosecco Day
nae nae

Nae Nae Day
pumpkin

Pumpkin Day
self appreciation

Self Appreciation Day
girl friend

Girl Friend Day
gallery

Gallery Day
fiancee

Fiancee Day
get funky

Get Funky Day
carpenters

Carpenters Day