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

Other days

get funky

Get Funky Day
ruby

Ruby Day
ride the wind

Ride The Wind Day
bonang

Bonang Day
china

China Day
one

One Day
lumpy rug

Lumpy Rug Day
carpenters

Carpenters Day
pick me

Pick Me Day
artists

Artists Day