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

Other days

fiancee

Fiancee Day
coffee

Coffee Day
bow tie

Bow Tie Day
bounce

Bounce Day
blanket fort

Blanket Fort Day
bubble bath

Bubble Bath Day
frozen yogurt

Frozen Yogurt Day
comfy

Comfy Day
first love

First Love Day
tulip

Tulip Day