Oops, it doesn't look like 'heave your guts out day' is a national day..

Other days

bounce

Bounce Day
china

China Day
one

One Day
lumpy rug

Lumpy Rug Day
brow

Brow Day
bubble bath

Bubble Bath Day
believe

Believe Day
gum

Gum Day
slime

Slime Day
prosecco

Prosecco Day