The Error in the Year 2033
Traditionally, the Chinese believes that the Leap Month would follow the 7th Month and the Chinese Lunar New Year starts on the 2nd New Moon after the Winter Solstice.
However, in early 1990s, Chinese Astronomers discovered that there was an error in the Chinese Calendar for the year 2033, and in the year 2034, Chinese Lunar New Year will begin on the 3rd new moon following the Winter Solstice.
In 2033, the Leap Month comes after the 11th month, and according to calculations, it have not happened since the Chinese Lunar Calendar was reformed in 1645.
Many other Chinese Astronomers claimed that there will never be a leap month after the 12th and 1st month. But, there will be a Leap Month after the 1st month in 2262 and it should have happened in 1651 ! There could also be a Leap Month after the 12th month in 3358.