Todays Google Doodle has recognised Africa Day. Africa Day is meant to celebrate the founding of Organisation of African Unity on 25th May 1963. The OAU charter was signed on that date and only Morocco has not joined the now called Africa Union. Africa Union replaced OAU in 2002.
The first Google Doodle was in 1998 and it was in honor of the burning man festival. Successive Doodles have been created and with Google opening country offices and purchasing country level domains, it has been even localised. We are though not sure if the Doodles which are restricted to cTLDs are designed locally or not.