Oops, it doesn't look like 'party convention day' is a national day..

Other days

frozen yogurt

Frozen Yogurt Day
pampering

Pampering Day
artists

Artists Day
ruby

Ruby Day
ponytail

Ponytail Day
tulip

Tulip Day
comfy

Comfy Day
unicorn

Unicorn Day
latina equal pay

Latina Equal Pay Day
brow

Brow Day