<p>A day on the moon lasts 29.53 days (a synodic month), slowing down by 0.005 seconds every century. <a href="https://en.wikipedia.org/wiki/Orbit_of_the_Moon" rel="nofollow noreferrer">ref</a>.</p>
<p>The tilt of 1.54' relative to the Sun has an 18.5996 years periodicity. <a href="https://en.wikipedia.org/wiki/Lunar_precession#Nodal_precession" rel="nofollow noreferrer">ref</a>.</p>

CC BY-SA 4.0
2023-08-27T06:44:58.910Z
2023-08-27T07:00:28.933Z
2023-08-27T07:00:28.933Z
bandybabboon
<p>The inclination of the lunar equator to the ecliptic is 1.543°.
Synodic period or Length of a day on the moon = 708.7344 hours</p>
<p><a href="https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html" rel="nofollow noreferrer">Moon Fact Sheet</a></p>
<p><a href="https://svs.gsfc.nasa.gov/12739" rel="nofollow noreferrer">100 Lunar Days - Parts I and II</a></p>

CC BY-SA 4.0
2023-08-26T15:20:52.917Z
Hi, and welcome to SE. Can you try to formulate your question as you would ask a normal person? How do the random "facts" in your question relate to the *several* questions you ask in telegram style in the headline? Try to focus on *one* question. Please outline your own attempts in finding an answer and why and how they were unsuccessful. Please see https://astronomy.stackexchange.com/help/how-to-ask
planetmaker
CC BY-SA 4.0
2023-08-26T16:52:07.813Z
A year is a year, no matter where you are.  Asking "how long is a year on ..." is generally a layman's method of asking about the orbital period around its parent body, and you already know that from your link.  If you want to ask something else, you will need to more clearly specify what you mean.
Greg Miller
CC BY-SA 4.0
2023-08-26T19:17:16.777Z
Thanks for the reply. Okay so I got the synodic period of the Moon (or a day on the moon) which is equal to 29.5306 mean solar days on earth . Now dividing mean solar year of earth 365.242 days (which I assume the time it takes for the earth-moon system to complete an orbit around the sun) by 29.5306 , I get 12.368.  Therefore there are only about 12.368 lunar days in a lunar year. Is this correct ? For clarification I am trying to get the orbital parameters of the moon for its orbit about the Sun
Śipiviṣṭa
CC BY-SA 4.0
2023-08-27T06:00:51.660Z
Please try to follow planetmaker's advice and fix your question. Especially, try to focus on one question.
PM 2Ring
CC BY-SA 4.0
2023-08-27T06:03:10.980Z
Since you're interested in the Moon's heliocentric orbit why are you concerned with the number of lunar days in a lunar year? Note that there are various ways to define the year: https://en.wikipedia.org/wiki/Year#Astronomical_years For orbit calculations, you probably want the anomalistic year.
PM 2Ring
<the-moon><orbital-elements><ecliptic><sidereal-period><synodic-period>
What is the duration of a year on the Moon (Tropical/Sidereal period) for orbit about the Sun ? How/why does length of lunar days vary ? Soltices?
Śipiviṣṭa
# What is the duration of a year on the Moon (Tropical/Sidereal period) for orbit about the Sun ? How/why does length of lunar days vary ? Soltices?

(Asked by: username_0 on 2023-08-26)

The inclination of the lunar equator to the ecliptic is 1.543°.
Synodic period or Length of a day on the moon = 708.7344 hours

[Moon Fact Sheet](https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html)

[100 Lunar Days - Parts I and II](https://svs.gsfc.nasa.gov/12739)

**Tags:** the-moon, orbital-elements, ecliptic, sidereal-period, synodic-period
> **Comments:**
> **username_1**: Hi, and welcome to SE. Can you try to formulate your question as you would ask a normal person? How do the random "facts" in your question relate to the *several* questions you ask in telegram style in the headline? Try to focus on *one* question. Please outline your own attempts in finding an answer and why and how they were unsuccessful. Please see https://astronomy.stackexchange.com/help/how-to-ask  
> **username_2**: A year is a year, no matter where you are.  Asking "how long is a year on ..." is generally a layman's method of asking about the orbital period around its parent body, and you already know that from your link.  If you want to ask something else, you will need to more clearly specify what you mean.  
> **username_0**: Thanks for the reply. Okay so I got the synodic period of the Moon (or a day on the moon) which is equal to 29.5306 mean solar days on earth . Now dividing mean solar year of earth 365.242 days (which I assume the time it takes for the earth-moon system to complete an orbit around the sun) by 29.5306 , I get 12.368.  Therefore there are only about 12.368 lunar days in a lunar year. Is this correct ? For clarification I am trying to get the orbital parameters of the moon for its orbit about the Sun  
> **username_3**: Please try to follow planetmaker's advice and fix your question. Especially, try to focus on one question.  
> **username_3**: Since you're interested in the Moon's heliocentric orbit why are you concerned with the number of lunar days in a lunar year? Note that there are various ways to define the year: https://en.wikipedia.org/wiki/Year#Astronomical_years For orbit calculations, you probably want the anomalistic year.  

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## 1 answers

### Answer by username_4 on 2023-08-27. Score: 1 | Accepted answer

A day on the moon lasts 29.53 days (a synodic month), slowing down by 0.005 seconds every century. [ref](https://en.wikipedia.org/wiki/Orbit_of_the_Moon).

The tilt of 1.54' relative to the Sun has an 18.5996 years periodicity. [ref](https://en.wikipedia.org/wiki/Lunar_precession#Nodal_precession).


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