Indians participate in a laughter club gathering as they celebrate World Laughter Day at the Nana Nani Park in Mumbai on May 7, 2017. World Laughter Day takes place on the first Sunday of May. The first celebration in India was on January 10, 1998, and was arranged by Dr. Madan Kataria, founder of the worldwide Laughter Yoga movement. Photos: Kunal Patil/Hindustan Times/Getty Images /CFP