Oops, it doesn't look like 'take a picture with an elephant while covering your mouth and pointing to a cloudy sky day' is a national day..

Other days

Slime Day

Brow Day

Singles Day

Prescription Drug Take Back Day

Girl Friend Day

Embarrass Your Best Friend Day

Ask Out Your Crush Day

Ormille Day

Tell Ur Crush You Like Them Day

Polyamory Day