Oops, it doesn't look like 'piss off stephen day' is a national day..

Other days

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
hiv awareness

Hiv Awareness Day
emoji

Emoji Day
prosecco

Prosecco Day
ask out your crush

Ask Out Your Crush Day
gum

Gum Day
azonto is acceptable

Azonto Is Acceptable Day
unicorn

Unicorn Day
frozen yogurt

Frozen Yogurt Day
kiss a brunette

Kiss A Brunette Day