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

Other days

stress awareness

Stress Awareness Day
ponytail

Ponytail Day
bow tie

Bow Tie Day
self appreciation

Self Appreciation Day
cat girl

Cat Girl Day
eat what you want

Eat What You Want Day
hiv awareness

Hiv Awareness Day
emoji

Emoji Day
cuddle up

Cuddle Up Day
tell a fairytale

Tell A Fairytale Day