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

Other days

fiancee

Fiancee Day
tulip

Tulip Day
boy friend

Boy Friend Day
ormille

Ormille Day
pick me

Pick Me Day
ride the wind

Ride The Wind Day
unicorn

Unicorn Day
cuddle up

Cuddle Up Day
first love

First Love Day
kale

Kale Day