Oops, it doesn't look like 'sibling or pet day' is a national day..

Other days

stud

Stud Day
pumpkin

Pumpkin Day
ruby

Ruby Day
self care

Self Care Day
cuddle up

Cuddle Up Day
kale

Kale Day
buddy

Buddy Day
pick me

Pick Me Day
bounce

Bounce Day
self appreciation

Self Appreciation Day