Article 12 Detailed information of the regulations.

Beginning of spring in the first month, stinging in February, Qingming in March, long summer in April, awning seeds in May, slight heat in June, beginning of autumn in July, white dew in August, cold dew in September, beginning of winter in October, heavy snow in November and slight cold in December.

December is dominated by December, which is called the Moon Building. Architecture, known as the Big Dipper in ancient astronomy, is short for architecture in bucket handle. The lunar month depends on this. Bucket handle refers to the first month of the lunar calendar, which begins with yin, that is, the first month of the lunar calendar is the beginning of the year, the first month of the lunar calendar is built in Yin, the second month of Mao Jian, the third month of Chen Jian, the fourth month of Si Jian, the fifth month of Wu Jian, the sixth month of June, the seventh month of Shen Jian, the eighth month of You Jian, the ninth month of Wan Jian, the tenth month of Hai Jian, the eleventh month of Zi Jian and the twelfth month of Ugly Jian.

As for what it means, I don't quite understand. It should be a method of dividing the lunar calendar.