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

Other days

kiss a ginger

Kiss A Ginger Day
bounce

Bounce Day
singles

Singles Day
coffee

Coffee Day
bow tie

Bow Tie Day
no bra

No Bra Day
hiv awareness

Hiv Awareness Day
slime

Slime Day
cursing

Cursing Day
lash

Lash Day