In some Asian countries, like Japan and China, 12 kinds of animal symbols are assigned to every single year by rotation; a mouse, cow, tiger, rabbit, dragon, snake, horse, sheep, monkey, chicken, dog, or boar. Once the boar finishes, it revolves back to the mouse. I was born in the year of the dog and I'm referred to as a man of the year in the year of dog, i.e. every 12 years. Every year, people at the age of multiples of 12 such as 12, 24, 36, 48, 60, 72, 84, 96, 108 and 120 (if alive) are called a man or woman of the year, because they were born in the same Zodiac symbol's year. 2012 is the year of the dragon and next year will be the year of the snake. Snakes are considered auspicious in 2013 and lots of items associated with them would be found across the country.
Additionally, there's another system that rotates 10 kinds of symbols. One system has 12 kinds of animal symbols and the other has 10 kinds. Considering the combination of both systems, all the years come to rotate every 60 years. The age of 60 is called "Kanreki", which means the full rotation of the years, and is regarded as auspicious.
Did you understand the rough explanation of 60 years, Kanreki in Japanese?
The picture shows the second party of the 19th graduates. All of them are leading figures in their respective fields.