Oops, it doesn't look like 'slide in my dms day' is a national day..

Other days

artists

Artists Day
kale

Kale Day
slime

Slime Day
martini

Martini Day
china

China Day
prosecco

Prosecco Day
blanket fort

Blanket Fort Day
polyamory

Polyamory Day
ride the wind

Ride The Wind Day
first love

First Love Day