Oops, it doesn't look like 'box her baby daddy day' is a national day..

Other days

boba

Boba Day
hannah

Hannah Day
get funky

Get Funky Day
hoodie

Hoodie Day
fiancee

Fiancee Day
comfy

Comfy Day
pick me

Pick Me Day
eat what you want

Eat What You Want Day
youth

Youth Day
book

Book Day