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

Other days

lisp

Lisp Day
unicorn

Unicorn Day
kiss a ginger

Kiss A Ginger Day
ride the wind

Ride The Wind Day
get funky

Get Funky Day
bonang

Bonang Day
stress awareness

Stress Awareness Day
lumpy rug

Lumpy Rug Day
bow tie

Bow Tie Day
brow

Brow Day