Tropical zodiac

The tropical zodiac is based upon tropical time, or the apparent motion of the sun's zenith across the sky over the course of a year. It is currently divorced from the actual constellations of the zodiac due to the Precession of the equinoxes. This is in contrast to the sidereal zodiac, which is based on the apparent motion of the zodiac itself. The tropical zodiac continues to be used by the majority of western astrologers.