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

Other days

gum

Gum Day
frozen yogurt

Frozen Yogurt Day
kale

Kale Day
self appreciation

Self Appreciation Day
law

Law Day
get funky

Get Funky Day
boy friend

Boy Friend Day
comfy

Comfy Day
stud

Stud Day
pampering

Pampering Day