"It is rare to meet the spring in a hundred years, and it is rare to meet the first month of the leap month in a thousand years", this ancient saying describes the preciousness and rarity of the leap month and the first month of the leap month. In the traditional Chinese calendar, leap months appear to make up for the time difference between the lunar and solar calendars. The lunar calendar has a total of 12 months in a year, while the solar calendar has about 365 months in a year2425 days, so the lunar calendar is about 11 days shorter than the solar calendar. In order to keep the lunar and solar calendars in sync, we introduced the concept of leap months.
The setting of the leap month is not arbitrary, it is related to the twenty-four solar terms. The 24 solar terms are based on the cycle of the earth's revolution around the sun, with a gap of about 15 days between each solar term and the middle of the solar term. Due to the uneven speed of the earth, the interval between the two solar terms before and after the winter solstice is shorter, which may be less than 30 days;The interval between the two solar terms before and after the summer solstice is longer, which may exceed 30 days. As a result, leap months are more likely to occur in the summer and less often in the winter.
In the way of setting leap months, the ancients adopted the law of seven leaps in 19 years, that is, 7 out of 19 years were leap months. The setting of a leap month is determined based on the presence or absence of mid-air. Zhongqi refers to the moment when the sun passes through the ecliptic longitude, which, together with the 24 solar terms, forms the basis of the lunar calendar. When it is estimated that there is no neutral air in a certain month, it is necessary to set a leap month.
A leap month generally refers to the addition of a wax month, that is, the addition of a wax month at the time when it should be a wax month. Therefore, the leap month and the first month of the leap month refer to the wax month and the first month of the leap year. According to traditional Chinese Xi, if there is a leap month, it will generally pass the first month and not the leap month. Therefore, even if there is a leap month, there will only be one leap year and not a leap year.
For the statement that "it is rare to meet the spring in a hundred years", we can verify it by looking up the perpetual calendar. In the past 100 years, there have indeed been many times when the beginning of spring and the first day of the new year are the same day. For example, in 1924 and 1943, the Spring Festival and the beginning of spring were the same day. Although this is a phenomenon that has occurred many times in a hundred years, it is not a "once-in-a-century event" as the proverb says.
And for the "millennium rare leap month", it is indeed very rare. In recorded time, the month of leap has occurred only twice, in 208 and 1574 AD. In addition, there will be no more intercalary months in the next few hundred years, and the next one will not occur until 3358. This also means that it is difficult for most of us to have the opportunity to witness the arrival of the leap month in person.
Compared with the leap month, the first month of the leap month occurs more frequently. According to historical records, the last leap month occurred in 1640 in the 17th century, and the next leap month was not until 2362 in the 23rd century. Although the frequency of leap months is higher, it is still relatively rare compared to the regular lunar calendar.
Leap months arose to keep the timing of the lunar and solar calendars in sync, to avoid the dislocation of the four seasons, and to maintain the traditions and culture of the lunar calendar. Although the occurrence of leap months and leap months is relatively rare, their existence is of great significance to people.
In short, although "a hundred years of rare spring, a thousand years of rare leap month" is a visual description of the leap month and the first month of the leap month, in reality, the appearance of the leap month is not once in a hundred years, and the appearance of the leap month is a thousand years of occurrence. These rare phenomena make people cherish and look forward to it more, and also provide us with a unique perspective and opportunity to understand and inherit the traditional Chinese calendar.
Through the leap month, we can see the wisdom behind the calendar and people's precise grasp of time. The addition of leap months is to adjust the difference between the lunar and solar calendars, to ensure the accuracy of the time and the inheritance of traditional culture. Although the occurrence of leap months is relatively rare, it has an important place and significance in the calendar system. At the same time, we can also appreciate people's cherishing of traditional festivals and respect for time, whether it is a New Year or a leap month, the atmosphere of reunion and celebration will not change.