In lunar calendars, a lunar month is the time between two successive syzygies of the same type: new moons or full moons. The precise definition varies, especially for the beginning of the month. Animation of the Moon as it cycles through its phases, as seen from the Northern Hemisphere. The apparent wobbling of the Moon is known as libration.

A lunar month, or a lunar cycle, is also known as a lunation. The astronomical term is a synodic month, from the Greek term synodos, meaning meeting or conjunction. An average lunar month lasts 29.530575 days or 29 days, 12 hours, 44 minutes, and 2 seconds, a few days short of a calendar month.

Lunar calendar year 2025. A lunar calendar is a calendar based on the monthly cycles of the Moon's phases (synodic months, lunations), in contrast to solar calendars, whose annual cycles are based on the solar year.The most widely observed purely lunar calendar is the Islamic calendar. [a] A purely lunar calendar is distinguished from a lunisolar calendar, whose lunar …

2021年1月1日 · Bottom line: In 2021, the longest lunar month happens between the April 12 and May 11 new moons, and the shortest one between the October 6 and November 4 new moons.

2020年2月1日 · The synodic lunar month is defined by the visible phases of the Moon. The length of a synodic lunar month ranges from 29.18 days to 29.93 days. The sidereal lunar month is defined by the Moon's orbit with respect to the stars. The length of a …

Lunar calendar, any dating system based on a year of synodic months—i.e., complete cycles of phases of the Moon. In every solar year there are about 12.37 synodic months. Therefore, if a lunar calendar is to be kept in step with the solar calendar, a periodic addition of days is …

The Chinese calendar has 12 or 13 lunar months per year, and is about 20 to 50 days behind the Gregorian calendar. It's used to determine the dates of traditional Chinese festivals , like Chinese New Year and Mid-Autumn.

Lunar Months. Lunar months are determined by the phases of the moon, from one new moon to the next. Here are some key points to consider: Duration: A lunar month typically lasts about 29.5 days, which is slightly shorter than the average solar month.

The Lunar Calendar gives to the dates of the new, first quarter, full, and last quarter moon each month of the year. A new moon is the first lunar phase that happens about once a month or, 29.53 days on average.

A lunation, or lunar month, is the time it takes the Moon to pass through all of the Moon phases, measured from one new moon to the next New Moon. The astronomical term for a lunation is a synodic month, from the Greek term synodos, meaning meeting or conjunction.