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

Other days

embarrass your best friend

Embarrass Your Best Friend Day

boyfriend

Boyfriend Day

Emoji Day

prosecco

Prosecco Day

believe

Believe Day

girl friend

Girl Friend Day

ask out your crush

Ask Out Your Crush Day

nail polish

Nail Polish Day

appreciate yaself a lil extra

Appreciate Yaself A Lil Extra Day

cursing

Cursing Day