Cosplayers dressed as Star Wars characters Chewbacca (R) and Darth Vader talk at a Star Wars Day fan event in Tokyo May 4, 2015. Star Wars fans celebrate May 4 as Star Wars Day, a pun that comes from an iconic quote in the movie, “May the Force be with you”. (Photo by Toru Hanai/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)

A Mai-Mai rebel soldier shows off his guns at a checkpoint near the Mugunga refugee camp in Zaire; 1996. (Photo by Carol Guzy/The Washington Post)

Police officers detain a demonstrator as people protest to defy a ban and march on Taksim Square to celebrate May Day in Istanbul, Turkey on May 1, 2023. (Photo by Dilara Senkaya/Reuters)

Bangladeshi farmers carry harvested produce in a cultivated field ahead of the 14 May World Farmers Day in Chittagong, Bangladesh on May 12, 2022. (Photo by Mohammad Shajahan/Anadolu Agency via Getty Images)

Nursing students attend a capping ceremony on May 10, 2021 in Jinan, Shandong Province of China. International Nurses Day is observed annually on May 12. (Photo by Zhang Yong/China News Service via Getty Images)

Sumo wrestlers of Nishonoseki clan appeal to the winner of a training bout for the next opponent during a joint training session ahead of the May Grand Sumo Tournament in Tokyo May 2, 2015. (Photo by Toru Hanai/Reuters)

A child parades on a float during the Bun Festival on May 25, 2015 in Hong Kong, Hong Kong. One of Hong Kong's most colourful cultural celebration event, Cheung Chau Bun Festival, will be staged on 25 May 2015 (Monday) till 26 May 2015 midnight (Tuesday). This festival has over 100 years of history. Every year, thousands of people descend upon the tiny island for The Piu Sik (Floating Colours) Parade, Lucky Bun (Ping On Bun) and The Bun Scrambling Competition, the ancient custom during the festival. (Photo by Lam Yik Fei/Getty Images)