Oops, it doesn't look like 'league adopted the stolen base rule day' is a national day..

Other days

fiancee

Fiancee Day
bow tie

Bow Tie Day
tell a fairytale

Tell A Fairytale Day
stud

Stud Day
hot chocolate

Hot Chocolate Day
coffee

Coffee Day
special education

Special Education Day
hiv awareness

Hiv Awareness Day
self appreciation

Self Appreciation Day
chocolate milkshake

Chocolate Milkshake Day