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

Other days

unicorn

Unicorn Day
gallery

Gallery Day
eat what you want

Eat What You Want Day
tulip

Tulip Day
gum

Gum Day
nae nae

Nae Nae Day
offer

Offer Day
book

Book Day
frozen yogurt

Frozen Yogurt Day
ormille

Ormille Day