The calculation is as follows:

The Monkey King was born around 578 BC (the date of birth is calculated separately, so I won't elaborate here).

According to The Journey to the West:

1, the Monkey King once saw that he was 342 years old in the book of life and death in hell. This is 342 years. After that, the Monkey King became Bi Marvin in heaven for half a month, which is about 15 years on earth. This is 15 year. Later, the Monkey King came down to earth to show his pole as a flag, and was called "Monkey King". I once said to Monkey Sun in Guo Hua, "I remember it was only six months ago. How can we talk about it for a hundred years?" In ancient times, there were about 360 days in a year and 180 days in half a year. Heaven is 180 days. The mortal world is 180. This is 180.

2. After that, the Monkey King was arrested by Erlang God after stealing Dan Tao. At this time, according to the previous calculation, it is 578 BC +342 BC +65438 BC+05 BC +65438 BC +080 = 465438 AD 0. This is a critical period, because the second battle between Yang and Sun was 800 years later.

3. In the future, in the 13th year of Zhenguan, the Monkey King was crushed by Wuxing Mountain to regain her freedom, that is, in 640 AD. In 14, the Monkey King escorted Tang Priest to the West to learn Buddhist scriptures, that is, he completed the Buddhist scriptures around 654 AD. Journey to the West is over.

{Note} In Lotus Lantern, the Monkey King, who has defeated the Buddha, said to Erlang God that "it has been more than 800 years since the last battle". We can know the approximate time background of the lotus lantern: AD 4 1 +800 = AD 84 1. That is, the year of the late Tang Dynasty and the early Song Dynasty.

4. The Journey to the West ended in 654 AD, and the time background of the Lotus Lantern is around 84 1 year. So 84 1-654= 187. In other words, the Lotus Lantern occurred in 187 after the Journey to the West. Calculate the time error, about 200 years.