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

Other days

promposal

Promposal Day
azonto is acceptable

Azonto Is Acceptable Day
frozen yogurt

Frozen Yogurt Day
self care

Self Care Day
slime

Slime Day
china

China Day
cat girl

Cat Girl Day
pick me

Pick Me Day
gum

Gum Day
lash

Lash Day