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

Other days

martini

Martini Day
nail polish

Nail Polish Day
mean girls

Mean Girls Day
comfy

Comfy Day
bonang

Bonang Day
polyamory

Polyamory Day
lumpy rug

Lumpy Rug Day
get funky

Get Funky Day
china

China Day
gum

Gum Day