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

Other days

eat what you want

Eat What You Want Day
tell a fairytale

Tell A Fairytale Day
book

Book Day
bounce

Bounce Day
tell ur crush you like them

Tell Ur Crush You Like Them Day
frozen yogurt

Frozen Yogurt Day
ask out your crush

Ask Out Your Crush Day
boy friend

Boy Friend Day
ride the wind

Ride The Wind Day
singles

Singles Day