20 15 how to get to January 29 of the lunar calendar?

The number of days in the lunar month is variable, sometimes 29 days, sometimes 30 days.

The first day of each month in the lunar calendar is the day when the moon is completely black.

Lunar year is determined by 24 solar terms, and solar terms are determined by the sun. The first solar term of the lunar calendar is called rain, which is set on the day when the sun angle is 330 degrees. The other 23 solar terms are set on the day when the sun angle changes 15 degrees. The following table lists the names and definitions of the 24 solar terms:

Nominal angle Gregorian calendar date period

Beginning of spring 3 15 February 4th

Rain 330 February 19 29.8 days

Shocked 345 March 6

Vernal equinox 0 March 2 1 day 30.2 days

Qingming15 April 5

Grain Rain 30th April 20th 30.7 days.

May 6, 45 in the long summer.

Summer June 2 1 Day 3 1.2

Mangzhong 75 June 6

June 22nd, 90,31.4 days from summer solstice.

High temperature in summer105 July 7

Summer120 July 23rd 3 1.4 days

Beginning of autumn 135 August 8th

Summer150 August 23rd 3 1. 1 day.

Millennium165 September 8

Equinox180 September 23rd 30.7 days

Cold dew195101October 8

First frost 21010130. 1 day on October 24th.

Beginning of winter 225165438+1October 8th

Xiaoxue 240165438+221October 29.7

Heavy snow 255 65438+February 7

Winter solstice 270 65438+February 22nd 29.5 days

Slight cold 285 65438+1October 6

Great cold 300 65438+129.5 days on October 20th.

Among the 24 solar terms, 12 is the main solar term: rain, vernal equinox, Grain Rain, summer fullness, summer solstice, summer heat, autumn equinox, first frost, light snow, winter solstice and severe cold.

Lunar year is very different from astronomical year. The lunar calendar has twelve lunar months, 353, 354 or 355 days, which is about 1 1 day less than astronomy. In order to keep pace with the astronomical year, it is necessary to set up a leap year every three lunar years. There are thirteen months in a leap year, and the added months are called leap months.

The names of December in the lunar calendar are: the first month, February, March, April, May, June, July, August, September, October, winter and December.

It is difficult to determine the leap month of the lunar leap year. There are two rules:

One: The winter solstice must fall on the winter moon of the lunar calendar. If it doesn't fall, one month before the twelfth lunar month will become a leap year.

Two: If it is a leap year, the first month after the winter month without major solar terms will be designated as a leap month. Leap month uses the name of last month.

Lunar year takes 60 years as a cycle, and the name of each year is arranged by the word 10 Tiangan and the word 12 Dizhi. 10 working days: A, B, C, D, E, G, G, N, G. 12 branches are: Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai. 12 There are 12 zodiac animals and their corresponding animals: rats, cows, tigers, rabbits, dragons, snakes, horses, sheep, monkeys, chickens, dogs and pigs.

According to historical records, the Lunar New Year has passed 78 cycles. This year's Gregorian calendar is 1999, which is the 17 year of the 79th cycle, that is, the 4696th year of the lunar calendar.

To sum up, the China lunar calendar has the following six laws:

One: the law that the moon is completely black-the day when the moon is completely black is the first day of the lunar calendar. The lunar cycle depends on this.

24 solar terms's Law-24 solar terms divides the astronomical year into 24 equal parts with solar terms of 15 degrees. This law determines the relationship between the lunar calendar and the astronomical year.

Three: the winter solstice rule-the winter solstice must fall in the winter month of the lunar calendar. If it doesn't fall, one month before the twelfth lunar month will become a leap year.

Four: leap month rule-if it is a leap year, the first month after the winter month without major solar terms is designated as a leap month.

Five: 60-year cycle-Lunar New Year takes 60 years as a cycle.

The calculation of rule 1 and rule 2 must be based on the observation of Zijinshan Observatory in Nanjing, China.