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

Other days

gum

Gum Day
prosecco

Prosecco Day
donate your hair

Donate Your Hair Day
ruby

Ruby Day
coffee

Coffee Day
slime

Slime Day
ride the wind

Ride The Wind Day
stud

Stud Day
bonang

Bonang Day
lost sock memorial

Lost Sock Memorial Day