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

Other days

bounce

Bounce Day
boba

Boba Day
bow tie

Bow Tie Day
reading

Reading Day
self care

Self Care Day
tulip

Tulip Day
prosecco

Prosecco Day
ormille

Ormille Day
martini

Martini Day
my little pony

My Little Pony Day