Oops, it doesn't look like 'vanilla milkshake vanilla frappe day' is a national day..

Other days

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
ponytail

Ponytail Day
ormille

Ormille Day
unicorn

Unicorn Day
bow tie

Bow Tie Day
tell a fairytale

Tell A Fairytale Day
offer

Offer Day
believe

Believe Day
martini

Martini Day
eat what you want

Eat What You Want Day