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

Other days

camera

Camera Day
boba

Boba Day
ormille

Ormille Day
ruby

Ruby Day
cuddle up

Cuddle Up Day
promposal

Promposal Day
frozen yogurt

Frozen Yogurt Day
slime

Slime Day
hiv awareness

Hiv Awareness Day
nae nae

Nae Nae Day