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

Other days

get funky

Get Funky Day
polyamory

Polyamory Day
tulip

Tulip Day
bow tie

Bow Tie Day
prosecco

Prosecco Day
lash

Lash Day
china

China Day
cursing

Cursing Day
unicorn

Unicorn Day
self appreciation

Self Appreciation Day