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

Other days

boy friend

Boy Friend Day
my little pony

My Little Pony Day
boba

Boba Day
girl friend

Girl Friend Day
boyfriend

Boyfriend Day
ormille

Ormille Day
artists

Artists Day
bow tie

Bow Tie Day
promposal

Promposal Day
kale

Kale Day