农历乙巳蛇年是闰年，有一个闰六月，年长384天，比公历2025年多了19天。受闰六月影响，乙巳 蛇年内的一些农历节日，如七夕节等，都向后推迟。去年七夕节对应的公历日期是在8月10日，今年七 夕节对应的公历日期则落在了8月29日。 赖迪辉表示，21世纪这100年内，今年七夕节来得最晚。这样的年份还将有一次，是在2055年，而 最早七夕节则落在2006年，对应的公历日期为7月31日，这样的年份还将有两次，分别是2044年和2082 年。 七夕节是一个以爱情为主题的浪漫节日。这一天，我国民间有乞巧、晒书、拜月等习俗。"愿每一 个人都能在这一天，感受到传统节日的独特魅力。"赖迪辉说。（记者：周润健） 为了协调回归年与农历年的"时间差"，古人采用设置闰月的方法，即每隔两三年增加一个闰月，大 约在19个农历年当中有12个平年（每年12个月）、7个闰年（每年13个月）。这样操作，就使得农历年 的平均长度和回归年的平均长度基本相符，方便了公众的日常生产生活。 "天阶夜色凉如水，卧看牵牛织女星"，一年一度的七夕节即将到来。你知道吗？今年七夕节，本世 纪最晚！ 七夕节是我国传统民俗节日，固定在每年农历的七月初七，但它在公历中的日 ...

Core Viewpoint - The article discusses the traditional Chinese lunar calendar, its structure, and the phenomenon of leap months, emphasizing that leap months are a normal occurrence in the calendar system and not related to climate anomalies [1][10]. Group 1: Lunar Calendar Structure - The lunar calendar is based on the moon's orbit around the Earth and the Earth's orbit around the sun, making it a lunisolar calendar [1]. - A lunar month is determined by the lunar cycle, averaging 29.53 days, leading to a lunar year of approximately 354 or 355 days, which is about 11 days shorter than a solar year [5]. - To align the lunar calendar with the seasons, ancient astronomers implemented a leap month system, adding 7 leap months in a 19-year cycle [6]. Group 2: Leap Month Mechanism - The leap month is determined based on the presence of solar terms, which divide the Earth's orbit into 24 segments, ensuring that each lunar month contains a solar term [6]. - If a lunar month lacks a solar term, it is designated as a leap month, with the current example being "leap June" in 2023, which has 29 days [7]. Group 3: Historical Context and Climate Relation - Leap June occurrences are not rare, with six instances recorded in the current century, including years like 2017 and 2025 [10]. - Recent extreme heat has been mistakenly linked to the leap month phenomenon, but experts clarify that leap months are a standard calendrical occurrence and do not indicate climate anomalies [10].

Core Viewpoint - The article discusses the occurrence of a leap month in the lunar calendar, specifically the leap June in 2023, and explains the astronomical reasoning behind it [2][6]. Summary by Sections Lunar Calendar Explanation - The lunar calendar is based on the moon's orbit around the Earth and the Earth's orbit around the sun, making it a lunisolar calendar [2][6]. - A lunar month is approximately 29.53 days, leading to a lunar year of about 354 or 355 days, which is about 11 days shorter than a solar year of 365.24 days [6]. Leap Month Mechanism - To align the lunar calendar with the solar calendar, ancient astronomers introduced leap months, adding 7 leap months in a 19-year cycle [6]. - The placement of leap months is determined by the 24 solar terms, which divide the Earth's orbit into 24 segments [6]. Current Leap Month Details - In 2023, the leap month is designated as "leap June," occurring from July 25 to August 22, with only one solar term (Liqiu) present in this period [6]. - The leap month has 29 days, and the absence of a solar term in the preceding month led to its designation as a leap month [6]. Frequency of Leap Months - This century will see a total of six occurrences of leap June, specifically in the years 2017, 2025, 2036, 2055, 2074, and 2093 [7]. Climate Connection - The article clarifies that the recent extreme heat is not related to the leap month phenomenon, emphasizing that leap months are normal occurrences in the lunar calendar [8].