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

Other days

eat what you want

Eat What You Want Day
artists

Artists Day
unicorn

Unicorn Day
lumpy rug

Lumpy Rug Day
ponytail

Ponytail Day
ruby

Ruby Day
bow tie

Bow Tie Day
bonang

Bonang Day
bounce

Bounce Day
my little pony

My Little Pony Day