Oops, it doesn't look like 'letters of intent on the same day' is a national day..

Other days

hoodie

Hoodie Day
carpenters

Carpenters Day
african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
boba

Boba Day
first love

First Love Day
boy friend

Boy Friend Day
lumpy rug

Lumpy Rug Day
gum

Gum Day
ponytail

Ponytail Day
me

Me Day