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

Other days

youth

Youth Day
ask out your crush

Ask Out Your Crush Day
slime

Slime Day
ormille

Ormille Day
ride the wind

Ride The Wind Day
tulip

Tulip Day
unicorn

Unicorn Day
cuddle up

Cuddle Up Day
promposal

Promposal Day
lisp

Lisp Day