| 七月 - SUN | MONE | 可用 | WED | TITAL | 177 | -JULY SAT | | --- | --- | --- | --- | --- | --- | --- | | | | - 建党节 | 机 | 初九 | ব 初十 | տ | | ್ | 7 小暑 | 8 +四 | d 十五 | 10 十六 | 11 十七 | +7 | | 13 | == | 15 | 16 | 17 甘三 | 18 日四 | 19 日至 | | 20 | 21 | つ | 动 | 24 | 25 画六月 | 26 | | 27 | BZ 切四 | 初五 | 初六 | 31 | | | | 八月- | | | | | | -AUGUST | | --- | --- | --- | --- | --- | --- | --- | | SUN | MON | TUE | WED | 1710 | FRE | SAT | | | | | | | 1 建军节 | 初九 | | m+ | 4 十一 | 110 | 6 | 7 立秋 | 8 十五 | ਰੇ 十六 | | +0 | == | +九 | 13 | ...

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].