Kazakh troops march during a parade of the armed forces to mark the Defender of the Fatherland Day in Astana, May 7, 2014. (Photo by Mukhtar Kholdorbekov/Reuters)

Princess Diana relaxes on the sand during a visit to the beach on the Caribbean Island of Nevis January 4, 1993. (Photo by Mark Cardwell/Reuters)

A guard stands at Dityatki checkpoint, marking a 30 km (18-mile) zone around the Chernobyl nuclear power plant April 23, 2013. Ukraine will mark the 27th anniversary of the Chernobyl disaster, the world's worst civil nuclear accident, on April 26. (Photo by Gleb Garanich/Reuters)

Sri Lankan participants control their bulls during a traditional cart race to mark the Sri Lanka National New Year in Homagama near Colombo on April 23, 2017. The new year marked by both the majority Sinhalese and minority Tamil population fell on April 14. (Photo by Lakruwan Wanniarachchi/AFP Photo)

The moon rises behind the skyline and financial district in Toronto, November 25, 2015. (Photo by Mark Blinch/Reuters)

Dancers perform a routine at the Renault display at the Beijing International Automotive Exhibition in Beijing, Tuesday, April 26, 2016. (Photo by Mark Schiefelbein/AP Photo)

A supporter of the Houthi movement attends a rally marking the birth anniversary of Prophet Mohammed, in Sanaa, Yemen December 11, 2016. (Photo by Khaled Abdullah/Reuters)

Horses from the Garrison Savannah, who are involved in celebrations today to mark 50 years of Independence, are washed in the sea first thing in the morning on December 1, 2016 in Bridgetown, Barbados. Prince Harry is visiting the Caribbean marking the 35th Anniversary of Independence in Antigua and Barbuda and the 50th Anniversary of Independence in Barbados and Guyana. (Photo by Chris Jackson/Getty Images)