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

Other days

bow tie

Bow Tie Day
promposal

Promposal Day
self appreciation

Self Appreciation Day
ruby

Ruby Day
pampering

Pampering Day
slime

Slime Day
kale

Kale Day
tell a fairytale

Tell A Fairytale Day
unicorn

Unicorn Day
hannah

Hannah Day