The positions of the Astrological signs shown is referenced to an Ephemeris.

The majority of astrologers study tropical astrology, involving planetary positions referenced to the vernal (spring) equinox position along the ecliptic (the equinox being the center of Earth's rotational plane and Earth's orbital plane around the Sun).

An ephemeris is a mathematically precise listing of where the planetary bodies are located in the sky. Both astrologers and astronomers deem an accurate ephemeris very important.)

An ephemeris charts the movement of celestial bodies (planets, moons, etc.) and predicts their positions at a given time.

It tells you what planet is in what degree of the zodiac on what day; whether it is retrograde, stationary or direct; and most tell you the declination, or height above the celestial equator. Another section of the page is the aspectarian, which tells you what a planet is doing in terms of its aspects to other planets.