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

Other days

comfy

Comfy Day
slime

Slime Day
lisp

Lisp Day
ruby

Ruby Day
lost sock memorial

Lost Sock Memorial Day
self care

Self Care Day
carpenters

Carpenters Day
bubble bath

Bubble Bath Day
youth

Youth Day
ask out your crush

Ask Out Your Crush Day