Oops, it doesn't look like 'ice cream emoji day' is a national day..

Other days

unicorn

Unicorn Day
slime

Slime Day
coffee

Coffee Day
boy friend

Boy Friend Day
law

Law Day
frozen yogurt

Frozen Yogurt Day
bubble bath

Bubble Bath Day
emoji

Emoji Day
tell a fairytale

Tell A Fairytale Day
ruby

Ruby Day