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

Other days

pumpkin

Pumpkin Day
cuddle up

Cuddle Up Day
fiancee

Fiancee Day
gum

Gum Day
ask out your crush

Ask Out Your Crush Day
cursing

Cursing Day
ruby

Ruby Day
frozen yogurt

Frozen Yogurt Day
bubble bath

Bubble Bath Day
cat girl

Cat Girl Day