People carry a giant flag with a photograph of Cuba's retired leader Fidel Castro during the May Day parade on Havana's Revolution Square May 1, 2008.
Swiss riot police officers help an elderly man who was injured during May Day protests in Zurich May 1, 2008.
An International Workers' Day rally is reflected in an advertising billboard in Kiev, Ukraine, May 1, 2008.
Riot police try to detain a demonstrator during May Day rallies in Santiago, Chile, May 1, 2008.
There were other celebrations going on as well that happened to take place yesterday, according to the Reuters photos. A "demonstration" with burning cars in Germany. A donkey festival in Mexico. A People's Liberation Army Camp Open Day in Hong Kong.
And finally, a water buffalo:
A local artist takes part in a water buffalo painting competition at the Binatbatan Festival in Vigan, Ilocos Sur, north of Manila, Philippines, May 1, 2008.
Between my birthday and all the celebrations, May Day was one busy day.