Oops, it doesn't look like 'pee in the litter box day' is a national day..

Other days

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
martini

Martini Day
hiv awareness

Hiv Awareness Day
my little pony

My Little Pony Day
tell ur crush you like them

Tell Ur Crush You Like Them Day
cursing

Cursing Day
slime

Slime Day
pick me

Pick Me Day
first love

First Love Day
polyamory

Polyamory Day