October 21 Holidays

Back to the Future Day marks October 21, 2015, the date to which Marty McFly, Doc Brown, and Jennifer traveled in Back to the Future Part II — the date that fans celebrated in 2015 with hoverboard marketing campaigns, and that is now observed annually to celebrate the Back to the Future trilogy. National Apple Day was established in the UK in 1990 by Common Ground to celebrate the enormous variety of British apple cultivars — more than 2,300 documented varieties — and to promote heritage orchards as cultural and ecological assets. American Frog Day was established to raise awareness for North American frog species — more than 100 species face threats from habitat loss, disease, climate change, and the fungal infection chytridiomycosis, which has caused the greatest loss of vertebrate biodiversity in recorded history. Global Iodine Deficiency Disorders Prevention Day was established by the International Council for the Control of Iodine Deficiency Disorders to raise awareness for iodine deficiency — the leading preventable cause of intellectual disability worldwide, affecting an estimated 2 billion people.