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

Other days

polyamory

Polyamory Day
kale

Kale Day
comfy

Comfy Day
self care

Self Care Day
promposal

Promposal Day
ruby

Ruby Day
kiss a ginger

Kiss A Ginger Day
ponytail

Ponytail Day
singles

Singles Day
special education

Special Education Day