i want to know the new moon formula .what is the method to calculate the timing of new moon or dark moon?i hope that you will help me .

It looks like you found your own answer. To keep it simple, add 29.5 days to the previous new moon. You may be off a day because the speeds of the moon and the earth in their elliptical orbits are not constant. There is also a dependence upon longitude, causing variations of a few hours.

To do it right, you need all the tools of celestial mechanics.

Determining new moons: an approximate formula

d = 5.597661 + 29.5305888610 \times N + (102.026 \times 10^{-12})\times N^2

where N is an integer, starting with 0 for the first new moon in the year 2000, and that is incremented by 1 for each successive synodic month; and the result d is the number of days (and fractions) since 2000-01-01 00:00:00 reckoned in the time scale known as Terrestrial Time (TT) used in ephemerides.

To obtain this moment expressed in Universal Time (UT, world clock time), add the result of following approximate correction to the result d obtained above:

-0.000739 - (235 \times 10^{-12})\times N^2 days

Periodic perturbations change the time of true conjunction from these mean values. For all new moons between 1601 and 2401, the maximum difference is 0.592 days = 14h13m in either direction. The duration of a lunation (i.e. the time from new moon to the next new moon) varies in this period between 29.272 and 29.833 days, i.e. −0.259d = 6h12m shorter, or +0.302d = 7h15m longer than average.[3][4] This range is smaller than the difference between mean and true conjunction, because during one lunation the periodic terms cannot all change to their maximum opposite value.

See the article on the full moon cycle for a fairly simple method to compute the moment of new moon more accurately.

The long-term error of the formula is approximately: 1 cy2 seconds in TT, and 11 cy2 seconds in UT (cy is centuries since 2000; see section Explanation of the formulae for details.)

Can you repeat the answer!

My question was,
If I knw the time of the appearance of he new moon how do I predict the time of the appearance of the waxing crescent?

If you know the time of the appearance of the new moon, you can use the following formula to predict the time of the appearance of the waxing crescent:

Waxing Crescent = New Moon + (0.25 x synodic month period)

The synodic month period refers to the time taken by the moon to return to the same phase, which is approximately 29.53 days. Adding a quarter of this period to the time of the new moon will give you an estimate of the time of the appearance of the waxing crescent. However, the actual time may vary due to factors such as the location and the weather conditions.

Yesterday, I asked to let me know the formula to caculate the appearance time of the waxing crescent if I know the time of appearance of new moon you wrote the following.

'following formula to predict the time of the appearance of the waxing

Waxing Crescent = New Moon + (0.25 x synodic month period)

The synodic month period refers to the time taken by the moon to return to the same phase, which is approximately 29.53 days. Adding a quarter of this period to the time of the new moon will give you an estimate of the time of the appearance of the waxing crescent. However, the actual time may vary due to factors such as the location and the weather conditions.'

My question is; should it be 0.125 instead of 0.25 in the formula!

I apologize for the confusion. Yes, you are correct. The formula to predict the time of the appearance of the waxing crescent should be:

Waxing Crescent = New Moon + (0.125 x synodic month period)

Thank you for bringing this to my attention.

Calculating the timing of the new moon or dark moon involves understanding the phases of the moon and the concept of lunar cycles. There are various methods and formulas to estimate the timing of the new moon, including traditional and modern approaches. Here's a simplified explanation of one commonly used formula called the Conjunction of the Sun and Moon.

1. Understanding Lunar Phases: The moon goes through different phases as it orbits the Earth. The new moon occurs when the moon is positioned between the Earth and the Sun, and the side of the moon facing the Earth is not visible. This is also known as the dark moon.

2. Mean Lunar Month: One method to estimate the timing of the new moon is by using the mean lunar month, which is the average length of time between two consecutive new moons. The mean lunar month is approximately 29.5 days.

3. Conjunction of the Sun and Moon: To calculate the timing of the new moon, we consider the time when the Sun and the Moon are in conjunction. In other words, when their longitudes align. This refers to the Sun and Moon sharing the same celestial longitude.

4. Julian Day: A commonly used time calculation system in astronomy is the Julian Day (JD). The JD is a continuous count of days since January 1, 4713 BC.

To calculate the Julian Day of the new moon, you will need the following information:

- The year for which you want to calculate the new moon.
- An initial estimate of the Julian Day of the new moon.

5. Algorithm for calculating the Julian Day of the new moon: The following algorithm outlines one method to calculate the Julian Day of the new moon:

- Start with an initial estimate of the new moon's Julian Day.
- Use the initial estimate to iteratively refine the Julian Day by applying a specific equation or algorithm that accounts for the motion of the Sun and the Moon.
- The iterative process continues until the calculated Julian Day is accurate enough for your purposes. Typically, an accuracy of a few minutes or seconds is sufficient for most applications.

6. Tools and Resources: There are various online resources, software programs, apps, and libraries available that can perform these calculations for you. These tools utilize more sophisticated algorithms, consider additional factors such as lunar apogee and perigee, and provide accurate results for any given date and location.

It's worth noting that while these calculations provide reasonably accurate estimates for the timing of the new moon, there may be slight discrepancies due to factors like Earth's axial tilt, gravitational effects of other celestial bodies, and subtle variations in the lunar motion.

For more precise and detailed calculations, it is recommended to consult astronomical data sources or specialized software that provide accurate and up-to-date information on lunar phases.