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

Other days

kale

Kale Day
stud

Stud Day
nae nae

Nae Nae Day
frozen yogurt

Frozen Yogurt Day
azonto is acceptable

Azonto Is Acceptable Day
pick me

Pick Me Day
ride the wind

Ride The Wind Day
prosecco

Prosecco Day
camera

Camera Day
book

Book Day