Staff members show smartphone cases with creative designs based on China's traditional 24 solar terms at a souvenir shop in Beihai Park, Beijing, capital of China, June 20, 2018. The 24 solar terms are a list of terms central to a calendar created in ancient China. Based on the movement of the sun, the calendar divides the year into 24 segments to guide farming over the four seasons. (Xinhua/Xing Guangli)

A staff member shows Rubik's Cubes with creative designs based on China's traditional 24 solar terms at a souvenir shop in Beihai Park, Beijing, capital of China, June 20, 2018. The 24 solar terms are a list of terms central to a calendar created in ancient China. Based on the movement of the sun, the calendar divides the year into 24 segments to guide farming over the four seasons. (Xinhua/Xing Guangli)