Following the September equinox, the sun had emerged above the northerly horizon, rising in long spirals until December 21.

从九月中的秋分日起，它在北方天际出现，沿着长长的螺旋线上升，直到12月21日。

Eventually people shifted the date from the September equinox to the 15th day of the 8th month on the Chinese lunar calendar.

最终，人们把祭祀日期从秋分时节改到了农历八月十五。

The Book of Rites recorded that Tianzi would worship the Sun on the March equinox, and worship the Moon on the September equinox.

《礼记》记载，天子会在春分时祭日，秋分时祭月。

One of these days occurs a few days before the March equinox, and the other is a few days after the September equinox.

其中一天发生在三月春分之前几天，另一天发生在九月春分之后几天。