Smile Power Day takes place on June 15, 2017. The day is a chance to give everyone you see a huge "I like you" smile! A smile is a facial expression formed by flexing the muscles near both ends of the mouth and by flexing muscles throughout the mouth. Among humans, it is an expression denoting pleasure, sociability, happiness, or amusement.
Smiling is something that is understood by everyone despite culture, race, or religion; it is internationally known. Cross-cultural studies have shown that smiling is a means of communication throughout the world. But there are large differences between different cultures. A smile can also be spontaneous or artificial. (With material from: Wikipedia)