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

Other days

ride the wind

Ride The Wind Day
get funky

Get Funky Day
stud

Stud Day
artists

Artists Day
cuddle up

Cuddle Up Day
tulip

Tulip Day
cursing

Cursing Day
nae nae

Nae Nae Day
boyfriend

Boyfriend Day
first love

First Love Day