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

Other days

bounce

Bounce Day
boba

Boba Day
lash

Lash Day
self care

Self Care Day
get funky

Get Funky Day
cuddle up

Cuddle Up Day
lisp

Lisp Day
comfy

Comfy Day
law

Law Day
fiancee

Fiancee Day