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

Other days

slime

Slime Day
ormille

Ormille Day
stud

Stud Day
pumpkin

Pumpkin Day
lash

Lash Day
self appreciation

Self Appreciation Day
buddy

Buddy Day
special education

Special Education Day
bubble bath

Bubble Bath Day
bow tie

Bow Tie Day