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

Other days

bounce

Bounce Day
polyamory

Polyamory Day
ruby

Ruby Day
prosecco

Prosecco Day
promposal

Promposal Day
get funky

Get Funky Day
latina equal pay

Latina Equal Pay Day
bow tie

Bow Tie Day
believe

Believe Day
lumpy rug

Lumpy Rug Day