The astrological signs that you see in your daily horoscope are 2500 years out of date due to the the axial precession of Earth, or "precession of the equinoxes". The constellations of the zodiac are those which appear on Terra's (Earth's) elliptic plane of revolution around Sol, our planetary system's star, progressively throughout the year. In addition to horoscope's zodiac being out of date, there are actually 13 constellations rather than 12. The "age" is whatever sign is dominant at the time of the spring equinox, in the current case, the Age of Pisces.
Pisces – 11 March-18 April
Aries – 18 April-13 May
Taurus – 13 May-21 June
Gemini – 21 June-20 July
Cancer – 20 July-10 August
Leo – 10 August-18 September
Virgo – 18 September-30 October
Libra – 30 October-23 November
Scorpius – 23 November-29 November
Serpentarius aka Ophiuchus – 29 November-17 December
Sagittarius – 17 December-20 January
Capricornus – 20 January-16 February
Aquarius – 16 February-11 March
The Greek astronomer Hipparchus (c. 190-120 BCE), founder of trigonometry, discovered that the constellations in the zodiac do not sit statically in the sky but "move" due to axial precession, or progression of the equinoxes. The discovery caused a revolution in science and philosophy and led directly to the mystery religion of Mithraism.