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

Other days

bonang

Bonang Day
lash

Lash Day
azonto is acceptable

Azonto Is Acceptable Day
tell a fairytale

Tell A Fairytale Day
slime

Slime Day
one

One Day
carpenters

Carpenters Day
buddy

Buddy Day
offer

Offer Day
bow tie

Bow Tie Day