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

Other days

kiss a brunette

Kiss A Brunette Day
cat girl

Cat Girl Day
promposal

Promposal Day
bonang

Bonang Day
cuddle up

Cuddle Up Day
blanket fort

Blanket Fort Day
comfy

Comfy Day
slime

Slime Day
brow

Brow Day
self care

Self Care Day