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

Other days

frozen yogurt

Frozen Yogurt Day
bow tie

Bow Tie Day
azonto is acceptable

Azonto Is Acceptable Day
boy friend

Boy Friend Day
emoji

Emoji Day
artists

Artists Day
me

Me Day
youth

Youth Day
ruby

Ruby Day
nae nae

Nae Nae Day