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

Other days

self appreciation

Self Appreciation Day
bounce

Bounce Day
azonto is acceptable

Azonto Is Acceptable Day
girl friend

Girl Friend Day
donate your hair

Donate Your Hair Day
ruby

Ruby Day
one

One Day
frozen yogurt

Frozen Yogurt Day
embarrass your best friend

Embarrass Your Best Friend Day
my little pony

My Little Pony Day