Aries (astrology) Aries (astrology) Aries (♈) (meaning "ram") is the first astrological sign in the zodiac, spanning the first 30 degrees of celestial longitude (0°≤ <30°). Under the tropical zodiac, the Sun transits this sign from approximately March 20 to April 21 each year. This time duration is exactly the first month of Solar Hijri calendar (Hamal/Farvardin/Wray). The symbol of the ram is based on the Chrysomallus, the flying ram that provided the Golden Fleece. According to the tropical system of astrology, the Sun enters the sign of Aries when it reaches the March equinox, which time systems and the western calendar
Zodiac used to determine the boundaries of astronomical constellations that lie in the vicinity of the zodiac, which are, and always have been, irregular in their size and shape. The convention of measuring celestial longitude within individual signs was still being used in the mid-19th century, but modern astronomy now numbers degrees of celestial longitude from 0° to 360°, rather than 0° to 30° within each sign. The use of the zodiac as a means to determine astronomical measurement remained the main method for defining celestial positions by Western astronomers until the Renaissance, at which time preference moved to the equatorial