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

Other days

bow tie

Bow Tie Day
aloxolt

Aloxolt Day
polyamory

Polyamory Day
get funky

Get Funky Day
china

China Day
prosecco

Prosecco Day
gum

Gum Day
latina equal pay

Latina Equal Pay Day
tulip

Tulip Day
lumpy rug

Lumpy Rug Day