International day of the girl: 'To my 15-year-old self' Today is International Day of the Girl -- a date on the annual calendar set aside to advocate for girls' rights and raise issues of gender bias. CNN spoke to some of the world's most remarkable and impressive women -- from across the fields of politics, science, media, sports and culture -- to find out: "Looking back, what one piece of advice would you give to your 15-year-old self?" By Lauren Said-Moorhouse, Ines Torre and Matthew Ponsford, for CNN. The wife of Microsoft co-founder Bill Gates, Melinda Gates is is a prominent American businesswoman and philanthropist as well as the co-chair of the Bill and Melinda Gates Foundation.