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

Other days

boyfriend

Boyfriend Day
ruby

Ruby Day
hiv awareness

Hiv Awareness Day
ask out your crush

Ask Out Your Crush Day
bow tie

Bow Tie Day
buddy

Buddy Day
cursing

Cursing Day
hannah

Hannah Day
carpenters

Carpenters Day
gallery

Gallery Day