Where does the longitude of the ecliptic begin, regardless of east longitude and west longitude?

Starting from the vernal equinox, 360 degrees from west to east, regardless of east and west longitude.

The ecliptic coordinate system is a coordinate system formed by the projection of the earth's revolution plane onto the celestial sphere, and the ecliptic is the measurement coordinate (longitude) on the ecliptic. According to astronomical practice, the vernal equinox is measured from west to east and divided into 360 degrees. The ancients in our country divided the 360-degree longitude of the sun into 24 equal parts, each equal part is 15 degrees, which is a solar term. The interval between two solar terms is about 15 days, and there are 24 solar terms throughout the year.

The longitude of the sun in 24 solar terms is: 3 15 degrees in beginning of spring, 330 degrees in rain, 345 degrees in fright, 360 degrees in vernal equinox, 30 degrees in Qingming 15 degrees in Grain Rain, 45 degrees in long summer, 60 degrees in childhood, 75 degrees in awn grass, 90 degrees in full summer solstice and 0/0 in summer. Millennium 165 degrees, autumnal equinox 180 degrees, cold dew 195 degrees, first frost 2 10 degrees, beginning of winter 225 degrees, light snow 240 degrees, heavy snow 255 degrees, winter solstice 270 degrees, slight cold 285 degrees and severe cold 3000 degrees.