A masked reveller poses along the flooded St. Mark's Square during a period of seasonal high water and on the first day of carnival, in Venice February 1, 2015. (Photo by Stefano Rellandini/Reuters)

A Swiss police officer accompanies a migrant from Syria carrying her baby, upon her arrival at the railway station in the north-eastern Swiss town of Buchs September 1, 2015. (Photo by Arnd Wiegmann/Reuters)

Swimmers in fancy dress splash as they participate in the New Year's Day Loony Dook swim at South Queensferry, Scotland January 1, 2015. (Photo by Russell Cheyne/Reuters)

A man with a painted face and traditional costumes takes part in the Schleicherlaufen festival in the western Austrian town of Telfs February 1, 2015. (Photo by Dominic Ebenbichler/Reuters)

A reveller walks through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Labourers work at the installation site of Liquefied Petroleum Gas (LPG) pipeline on May Day or Labour Day in Chandigarh, India, May 1, 2015. (Photo by Ajay Verma/Reuters)

Images are projected onto the Empire State Building as part of an endangered species projection to raise awareness, in New York August 1, 2015. (Photo by Eduardo Munoz/Reuters)

Firework display from the top of the Sky Tower to welcome the New Year on January 1, 2015 in Auckland, New Zealand. (Photo by Dave Rowland/Getty Images)