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

Other days

tell a fairytale

Tell A Fairytale Day
slime

Slime Day
special education

Special Education Day
cuddle up

Cuddle Up Day
boy friend

Boy Friend Day
lash

Lash Day
promposal

Promposal Day
offer

Offer Day
martini

Martini Day
healing

Healing Day