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

Other days

ruby

Ruby Day
believe

Believe Day
law

Law Day
kale

Kale Day
promposal

Promposal Day
nae nae

Nae Nae Day
prescription drug take back

Prescription Drug Take Back Day
bonang

Bonang Day
ponytail

Ponytail Day
self appreciation

Self Appreciation Day