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

Other days

fiancee

Fiancee Day
bubble bath

Bubble Bath Day
tulip

Tulip Day
self care

Self Care Day
bow tie

Bow Tie Day
camera

Camera Day
ride the wind

Ride The Wind Day
eat what you want

Eat What You Want Day
lisp

Lisp Day
nail polish

Nail Polish Day