Oops, it doesn't look like 'both finish the day' is a national day..

Other days

hoodie

Hoodie Day
ormille

Ormille Day
youth

Youth Day
kiss a brunette

Kiss A Brunette Day
one

One Day
cat girl

Cat Girl Day
cursing

Cursing Day
camera

Camera Day
boba

Boba Day
self care

Self Care Day