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

Other days

pampering

Pampering Day
donate your hair

Donate Your Hair Day
believe

Believe Day
singles

Singles Day
brow

Brow Day
youth

Youth Day
cuddle up

Cuddle Up Day
my little pony

My Little Pony Day
cat girl

Cat Girl Day
ruby

Ruby Day