Original sentence: If the position of the earth in its orbit around the sun is reckoned with respect to the equinox (the point at which the earth's orbit crosses the celestial equator), then the dates accurately indicate the season, that is, they are synchronized with the declination of the sun
Edited sentence: If the position of the earth in its orbit around the sun is reckoned with respect to the equinox, the point at which the orbit crosses the celestial equator, then the dates accurately indicate the season, that is, they are synchronized with the declination of the sun