Use the moon phase calculator on StarDate.org to determine when the next new moon occurs. Input the current month or a future month to see the expected phases of the Moon within that time frame.
The Moon orbits the earth every 27.3 days, but the lunar phase cycle from one new moon to the next new moon is 29.5 days. This 2.2-day remainder is a result of the fact that the Earth travels 45 million miles around the Sun in its own orbit during the time the Moon completes a single orbit around the Earth and subsequently has to catch up on the additional distance traveled.
During each new moon phase, the Moon travels close enough to the sun that no part of its surface visible to Earth is illuminated by the sun's light. This is in contrast to the full moon phase, wherein the totality of the Moon's earthward surface is visible due to its position relative to the Sun. The Moon always shows the same face to the Earth due to the effect of Earth's gravity slowing the celestial object's rotational speed; the Moon rotates in such a way as to compensate for the difference in angle that its orbit around the Earth produces, keeping one-half of its face aligned to the Earth.