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

Other days

first love

First Love Day
pumpkin

Pumpkin Day
slime

Slime Day
eat what you want

Eat What You Want Day
bonang

Bonang Day
reading

Reading Day
pampering

Pampering Day
brow

Brow Day
stud

Stud Day
gum

Gum Day