Oops, it doesn't look like 'flag hairpins become trendy in china in day' is a national day..

Other days

Prosecco Day

Cursing Day

Unicorn Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Tell Ur Crush You Like Them Day

Ruby Day

My Little Pony Day

First Love Day

Appreciate Yaself A Lil Extra Day

Brow Day