The traditional lunar calendar was based on Chinese astrology and used as a way to count years, months, days, and hours. Each of the 12 animals stands for a year in a 12-year cycle, a day in the 12-day cycle, and for every two hours in a 24-hour day.

Snake years are sixth in the cycle, following the dragon.

So where did the snake zodiac come from?

Legend has it, long ago, snakes and frogs were friends. Snakes had four legs then while frogs didn't. Crawling frogs worked very hard, not only did they seek food for snakes but also caught pests for human beings. Therefore human beings liked frogs and hated snakes.

So the story goes, snakes then turned vicious, they would bite human beings and animals whenever they got the chance. The Jade Emperor in heaven, informed of the snakes' vile ways, persuaded snakes to be kind, but the arrogant snakes refused. The Jade Emperor sent soldiers to cut off all snakes' legs and give them to frogs.

Frogs became more hard-working with legs. Legless snakes, determined to make a change, began eating pests for human beings and legend says they even learned to combat floods from dragons. They offered their body as medicine to treat patients.

In order to encourage snakes to do more good, the Jade Emperor put them into the Chinese zodiac list - sixth in the cycle, following the dragon.

After that, snakes didn't attack human beings all of the time, but if they did, occasionally driven by evil, they would cast off a layer of skin to show their determination to restart being kind. But snakes have always held a grudge against frogs, biting whenever the two meet.