Happy Chinese New Year!
The date of Chinese New Year is determined by the new moon, but also by the winter solstice. Thus, it is a solar and lunar New Year, as explained in this helpful article.
For discussions of the phases of the moon, and the cause of the new moon, see discussions in previous posts, such as this one and this one. The above video was stitched together from NASA images, and shows the phases of the moon as well as the phenomenon of lunar libration. As it orbits the earth, the moon presents the same face towards us at all times, but even as it does so it rocks slightly in a motion which is called "libration," and which can be seen in the video sequence.
For an amazing look at the dance of the earth and the moon in their orbit around the sun, see the video below:
After pondering the beautiful motion of the earth and the moon around their common "barycenter," you will undoubtedly develop a greater appreciation for the fact that the Chinese New Year takes into account both the sun and the moon in relation to the earth!
In Lost Light (discussed in this previous post), Alvin Boyd Kuhn put forth the thesis that the motions of the sun, moon, and other celestial bodies were seen by the ancients -- all over the world -- as typifying the descent of the human soul into incarnation in this life, and its re-ascent to the world of spirit, through the cycles of incarnation and re-incarnation by which, as he paraphrases the Egyptian Book of the Dead, "the soul steppeth onward through eternity"(41).
In discussing this subject, he writes:
Millions of intelligent persons today have looked upon sun and moon throughout the whole of their lives and have never yet discerned in their movements and phases an iota of the astonishing spiritual drama which the two heavenly bodies enact each month, a drama disclosed to our own astonished comprehension only by the books of ancient Egypt. 71.
But now that you know, you can contemplate this profound subject in the majestic cycles of the sun, moon, and stars, including in the cycles which bring about the annual Chinese New Year.
Happy Chinese New Year! Wishing you all peace, health, freedom, and consciousness in the New Year.