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

Other days

fiancee

Fiancee Day
lost sock memorial

Lost Sock Memorial Day
tulip

Tulip Day
unicorn

Unicorn Day
hannah

Hannah Day
eat what you want

Eat What You Want Day
stud

Stud Day
martini

Martini Day
blanket fort

Blanket Fort Day
buddy

Buddy Day