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

Other days

first love

First Love Day
kiss a brunette

Kiss A Brunette Day
kiss a ginger

Kiss A Ginger Day
pumpkin

Pumpkin Day
nae nae

Nae Nae Day
boba

Boba Day
ruby

Ruby Day
me

Me Day
carpenters

Carpenters Day
slime

Slime Day