As time goes by, the footsteps of the Lunar New Year are getting closer and closer. Recently, the phrase 'Next Chinese New Year's Eve will be in 2030 #' went viral, and some people were wondering why there wasn't a Chinese New Year's Eve this year? Regarding this, Professor Wang Juan from the Department of Chinese at Peking University stated in an interview with China News Service that the situation of "not having the 30th day of the Lunar New Year for five consecutive years" is indeed relatively rare, but "the disappearance of the 30th day of the Lunar New Year" is actually a normal calendar phenomenon. She mentioned that the lunar calendar we use is a very scientific and precise traditional calendar, belonging to the yin-yang combined calendar. The lunar calendar can be divided into small and large months, with the large month having 30 days and the small month having only 29 days. Which month is the major month and which month is the minor month is also determined according to the calendar. If the twelfth lunar month falls on a small lunar month, then naturally there will be no 'New Year's Eve'. What is' lunar calendar '? To explain the issue of "Chinese New Year's Eve", we need to first understand what "lunar calendar" is. According to Wang Juan, the lunar calendar is the traditional calendar we still use today, and it is also a combination of yin and yang. In ancient times, people established a solar calendar by observing the laws of the sun's movement, with a tropical year consisting of approximately 365 days. The 'lunar calendar', also known as the 'Tai Yin calendar', is formulated by people by observing the movement of the moon. The time of the first lunar month is called 'Shuo', and the time of the full moon is called 'Wang'. The average period of a synodic month is about 29.53 days, and the duration of a year is about 350 days, less than 360 days, "she said. However, due to the fact that the lunar calendar is compiled according to the lunar phase cycle, it does not accurately reflect the changes of the four seasons. The ancients utilized their intelligence and successfully solved this problem by setting leap months to regulate both the solar and lunar calendars. For example, the "Taichu Calendar" compiled by Deng Ping, Luo Xiahong and others in the Han Dynasty is a combination of yin and yang calendars. The "Taichu Calendar" takes the first month of Mengchun as the beginning of the year and stipulates that the month without qi is a leap month. In addition, she said that after continuous adjustments, the lunar calendar we are using now is very scientific and precise, which can reflect the changes of the four seasons and the laws of the moon's movement, and is very suitable for daily needs. The disappearance of Chinese New Year's Eve is not uncommon. For ancient societies that relied on lunar timing, the lunar calendar was actually very practical. Wang Juan explained that this is because the moon's movement pattern is easy to observe. On the first day of the lunar month, it is a new moon, and around the fifteenth day, it is a full moon. When the remaining moon disappears, it is the end of the month, which is simple and easy to remember, and can serve people's daily lives. The lunar calendar determines the months based on their phases, with an average of less than 30 days per month that needs to be adjusted. People have also flexibly solved this problem by dividing the lunar months into small and large months, with small months having 29 days and large months having 30 days. ”Wang Juan said. In this way, if the twelfth lunar month happens to coincide with the small lunar month, then there are only 29 days, which means there is no "Lunar New Year's Eve". She emphasized that the twelfth lunar month is the last month in the lunar calendar, and "New Year's Eve" refers to the last day of the lunar year, regardless of whether it has 29 or 30 days. Moreover, in most cases, the twelfth lunar month has 30 days, which is why people habitually refer to New Year's Eve as "New Year's Eve" or "New Year's Eve". Entering the twelfth lunar month, the flavor of the New Year gradually intensifies. Wang Juan said that in the past, the 23rd day of the twelfth lunar month meant the beginning of the Spring Festival. People cleaned, milled tofu, steamed Mantou, bought New Year goods, enjoyed life, and welcomed the arrival of the Spring Festival. (New Society)