When is the leap 11th month in the Gregorian calendar? Which years have a leap 11th month? The leap month is a special month in the Chinese lunar calendar. Some of them occur only once every hundred years. Visit Leap 11th Month section on Laihuayi.com to learn more about leap months.

When is the leap 11th month in the Gregorian calendar?

The leap 11th month occurs after the Winter Solstice and before the Great Cold, containing only the Minor Cold solar term. It corresponds to the zodiac sign Capricorn. Capricorn dates from December 22nd to January 19th, so the leap 11th month usually falls between late December of the Gregorian calendar and early January of the next year.
A leap month is a method of intercalation in the calendar. In China, a leap month specifically refers to an extra month added every two to three years. To reconcile the contradiction between the tropical year and the lunar year, and prevent the lunar calendar from becoming detached from the seasons, one leap month is added every two to three years.
The current method for adding a leap month in the lunar calendar is "seven leap months in nineteen years," meaning that an additional lunar month, identical to the previous one, must be added every two to three years. The rule for adding a leap month is determined based on the twenty-four solar terms related to the solar tropical year. A tropical year is divided into twenty-four solar terms. If the solar terms are arranged from Start of Spring to Great Cold, the odd-numbered ones are called "solar terms" (jieqi), while the even-numbered ones are called "mid-term" (zhongqi). The twelve mid-terms are used to represent the twelve months of the lunar year. The average interval between mid-terms is about one day longer than a lunar month. Over time, it will eventually result in mid-terms occurring at the end of the month. Therefore, the following month will inevitably have no mid-term and only contain a solar term (meaning the next mid-term will fall at the beginning of the second lunar month). This lunar month without a mid-term is called the leap month of the previous month.

Which years have a leap 11th month?

1593 (Gui Si), 1612 (Ren Zi), 1631 (Xin Wei), 1642 (Ren Wu)
2033 (Gui Chou), 2128 (Wu Zi), 2147 (Ding Wei), 2614 (Jia Wu)
2728 (Wu Zi), 2910 (Geng Yin), 3062 (Ren Wu), 3244 (Jia Zi)
3339 (Ji Hai), 3616 (Bing Zi), 3711 (Xin Hai), 3730 (Geng Wu)
3825 (Yi Si), 4007 (Ding Wei), 4159 (Ji Mao), 4197 (Ding Si)
4322 (Ren Wu), 4341 (Xin Si), 4531 (Xin Mao), 4599 (Ji Hai)