Oops, it doesn't look like 'anthem at westminster abbey armistice day' is a national day..

Other days

One Day

Chocolate Milkshake Day

Ride The Wind Day

Promposal Day

Unicorn Day

Tell Ur Crush You Like Them Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Hot Chocolate Day

Believe Day

Blanket Fort Day