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

Other days

lisp

Lisp Day
cat girl

Cat Girl Day
unicorn

Unicorn Day
get funky

Get Funky Day
prosecco

Prosecco Day
ruby

Ruby Day
tulip

Tulip Day
hoodie

Hoodie Day
azonto is acceptable

Azonto Is Acceptable Day
boba

Boba Day