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

Other days

bow tie

Bow Tie Day
kale

Kale Day
hannah

Hannah Day
mean girls

Mean Girls Day
boba

Boba Day
bubble bath

Bubble Bath Day
slime

Slime Day
self care

Self Care Day
frozen yogurt

Frozen Yogurt Day
tulip

Tulip Day