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

Other days

offer

Offer Day
coffee

Coffee Day
bow tie

Bow Tie Day
eat what you want

Eat What You Want Day
china

China Day
girl friend

Girl Friend Day
gum

Gum Day
boyfriend

Boyfriend Day
my little pony

My Little Pony Day
kale

Kale Day