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

Other days

bonang

Bonang Day
martini

Martini Day
cat girl

Cat Girl Day
gum

Gum Day
girl friend

Girl Friend Day
kiss a brunette

Kiss A Brunette Day
pick me

Pick Me Day
get funky

Get Funky Day
boyfriend

Boyfriend Day
book

Book Day