Oops, it doesn't look like 'convention was held day' is a national day..

Other days

bow tie

Bow Tie Day
stud

Stud Day
buddy

Buddy Day
ask out your crush

Ask Out Your Crush Day
prosecco

Prosecco Day
pick me

Pick Me Day
kale

Kale Day
hannah

Hannah Day
comfy

Comfy Day
boy friend

Boy Friend Day