Sunday motion of celestial bodies+annual motion of celestial bodies+unique Zhou Yue motion of the moon.
On the first day of the lunar calendar, the moon rises and sets with the sun.
After that, the moon moves eastward every day 13, and it appears 50 minutes later. On the seventh day (until the first quarter of the moon), the moon appeared in the western sky after sunset, and the brighter side became bigger and bigger later (from evening to midnight).
Later, on the fifteenth day of the lunar calendar, the moon appeared in the eastern sky after sunset. The later the moon set (from midnight to dawn), the brighter it became.
Then, on the 23rd day of the lunar calendar (the third day of the third month of the lunar calendar), the moon disappeared after the sun set, and it didn't rise until after the sun set. After sunrise, it is in the western sky, and its bright surface becomes smaller and smaller.
On the 29th/30th day of the lunar calendar, the moon rises later and later, rises after midnight, and appears in the eastern sky after sunrise, getting closer and closer to the sun and getting smaller on both sides. On the 29th and 30th day, it almost rises and falls with the sun, so it is impossible to observe.
After that, a new cycle began.
As for the convex direction, you can look at my following answer:
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