lunar calendar accuracy for predicting new moons I wonder, how accurate the lunar calendar is?
Can we predict the new moons precisely for tens of years in future?
If we know all factors that affects the movement of the moon, then why it is not possible to predict it?
The answer depends on what you mean with "precisely".  The ELP theory seems to have an accuracy of ~10-6&deg; in longitude over a century, which comes down to about a millisecond for phases.