Oops, it doesn't look like 'nylon no skirt day' is a national day..

Other days

boba

Boba Day
book

Book Day
offer

Offer Day
bow tie

Bow Tie Day
believe

Believe Day
coffee

Coffee Day
ask out your crush

Ask Out Your Crush Day
lash

Lash Day
china

China Day
blanket fort

Blanket Fort Day