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

Other days

tulip

Tulip Day
girl friend

Girl Friend Day
brow

Brow Day
self care

Self Care Day
latina equal pay

Latina Equal Pay Day
believe

Believe Day
no bra

No Bra Day
martini

Martini Day
kale

Kale Day
coffee

Coffee Day