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

Other days

pumpkin

Pumpkin Day
stud

Stud Day
get funky

Get Funky Day
nail polish

Nail Polish Day
law

Law Day
brow

Brow Day
promposal

Promposal Day
kiss a ginger

Kiss A Ginger Day
pick me

Pick Me Day
ormille

Ormille Day