People play Taiji on a square on August 08, 2011 in Luoyang, Henan Province of China. People all over China mark National Fitness Day on Monday in their own ways. (Photo by ChinaFotoPress/Getty Images)

Juri Mitomi, 20, holds a cigarette after a Coming of Age Day celebration ceremony at an amusement park in Tokyo January 12, 2015. According to a government announcement, more than 1.2 million men and women who were born in 1994 marked the coming of age this year, an increase of approximately 50,000 from last year. The increase is also the first since 1995. (Photo by Yuya Shino/Reuters)

A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

Israeli mounted policemen move crowds of Palestinian protestors during a demonstration marking Land Day in the east of the city on March 30, 2012 outside the old city of Jerusalem, Israel. Land Day, which began in 1976, marks the day Israeli forces killed six Palestinians during a protest against Israeli occupation of what Palestinians consider to be their land. Palestinians around the world will commemorate Land Day with protests and demonstrations. (Photo by Lior MizrahiGetty Images)

A mine detection rat is given banana as a reward after successfully identifying an inactive mine on July 2, 2015 in Siem Reap, Cambodia. The Cambodian Mine Action Center (CMAC) working with the Belgian NGO APOPO has recently begun testing the feasability of using large mine detection rats from Tanzania to help clear fields of mines and unexploded ordnance in one of the most bombed and mined countries in the world. (Photo by Taylor Weidman/Getty Images)

In this photo provided by Jean Revillard, Solar Impulse 2, a plane powered by the sun's rays and piloted by Andre Borschberg, approaches Kalaeloa Airport near Honolulu, Friday, July 3, 2015. His 120-hour voyage from Nagoya, Japan broke the record for the world's longest nonstop solo flight, his team said. (Photo by Jean Revillard/Global Newsroom via AP Photo)

People make their way on an algae-covered beach in Qingdao, Shandong province, China, July 19, 2015. (Photo by Reuters/Stringer)

A man carries his wife on his back as they make their way with their luggage along a flooded tunnel to catch their train, after heavy rainfall hit Jinhua, Zhejiang province, China, July 21, 2015. (Photo by Reuters/China Daily)