Tide half a day) varies in a two-week cycle. Approximately twice a month, around new moon and full moon when the Sun, Moon, and Earth form a line (a configuration known as a syzygy), the tidal force due to the Sun reinforces that due to the Moon. The tide's range is then at its maximum; this is called the spring tide. It is not named after the season, but, like that word, derives from the meaning "jump, burst forth, rise", as in a natural spring. When the Moon is at first quarter or third quarter, the Sun and Moon are separated
Chinese sun and moon mirrors moon-mirrors and beliefs that certain marine animals waxed and waned in correspondence with the moon. For example, the (c. 3rd century BCE) "Guanzi" says, The virtue of a ruler is what all the people obey, just as the moon is the root and fount of all Yin things. So at full moon, shellfish ["bangge" 蚌蛤] are fleshy, and all that is Yin abounds. When the moon has waned, the shellfish are empty and Yin things weak. When the moon appears in the heavens all Yin things are influenced right down to the depths of the sea. So the sage lets