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

Other days

china

China Day
first love

First Love Day
kale

Kale Day
ruby

Ruby Day
chocolate milkshake

Chocolate Milkshake Day
ride the wind

Ride The Wind Day
bonang

Bonang Day
artists

Artists Day
hot chocolate

Hot Chocolate Day
bounce

Bounce Day