Oops, it doesn't look like 'buy a book for a friend day' is a national day..

Other days

gum

Gum Day

china

China Day

ask out your crush

Ask Out Your Crush Day

eat what you want

Eat What You Want Day

ormille

Ormille Day

ruby

Ruby Day

boy friend

Boy Friend Day

embarrass your best friend

Embarrass Your Best Friend Day

Emoji Day

fiancee

Fiancee Day