Oops, it doesn't look like 'single and miserable day' is a national day..

Other days

boba

Boba Day
tulip

Tulip Day
cuddle up

Cuddle Up Day
kiss a ginger

Kiss A Ginger Day
hot chocolate

Hot Chocolate Day
book

Book Day
girl friend

Girl Friend Day
lash

Lash Day
brow

Brow Day
singles

Singles Day