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

Other days

ask out your crush

Ask Out Your Crush Day
lash

Lash Day
brow

Brow Day
bow tie

Bow Tie Day
reading

Reading Day
pampering

Pampering Day
pick me

Pick Me Day
youth

Youth Day
ruby

Ruby Day
polyamory

Polyamory Day