When does the waning moon refer to the lunar phase of the lunar calendar?

The waning moon is after the full moon. As the position of the sun and the moon approaches, the moon becomes thinner and thinner. It goes through several stages in turn: the convex moon, the lower quarter moon and the moth-eyebrow moon, and finally, it returns to the position of the new moon. China used to call the "moth eyebrow moon" in the second half of the month "the waning moon". The waning moon indicates sadness.

On the first day of each month in the lunar calendar, when the moon moves between the sun and the earth, the moon faces the earth with its dark side and rises and falls with the sun, so people can't see it. At this time, the moon phase is called "new moon" or "new moon".

After the new moon, the moon gradually moved out of the area between the earth and the sun. At this time, we began to see that a small part of the moon was illuminated by sunlight and shaped like a curved moth eyebrow, so the moon phase at this time was called "moth eyebrow moon". This "moth eyebrow moon" can only be seen in the western sky at night.

By the eighth day of the eighth lunar month, from the perspective of the earth, the moon has moved to 90 degrees east of the sun. At this time, we can see the bright half of the west of the moon. At this time, the moon phase is called "winding". The first quarter moon can only be seen in the first half of the night, and then disappears in the west at midnight.

After the first winding, the moon becomes round day by day, and we can see most of the bright hemispheres of the moon. At this time, the moon phase is called "convex moon".

On the fifteenth and sixteenth day of the lunar calendar, the moon runs across the celestial sphere to the opposite side of the sun, and the distance between the sun and the moon is 180, that is, the earth is located between the sun and the moon. Seen from the earth, all the light of the moon is directed towards the earth. At this time, the moon phase is called "full moon" or "full moon". The full moon rises in the east at dusk and sets in the west at dawn.