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

Other days

kale

Kale Day
hot chocolate

Hot Chocolate Day
lumpy rug

Lumpy Rug Day
believe

Believe Day
kiss a ginger

Kiss A Ginger Day
self care

Self Care Day
healing

Healing Day
hiv awareness

Hiv Awareness Day
brow

Brow Day
bow tie

Bow Tie Day