Quick Answer:
Your zodiac sign is determined by your birth date and time, based on the positions of the sun, moon, and planets in relation to Earth. The 12 signs are: Aries (March 21-April 19), Taurus (April 20-May 20), Gemini (May 21-June 20), Cancer (June 21-July 22), Leo (July 23-August 22), Virgo (August 23-September 22), Libra (September 23-October 22), Scorpio (October 23-November 21), Sagittarius (November 22-Dec. 21), Capricorn (Dec. 22-Jan. 19), Aquarius (Jan. 20-Feb. 18), Pisces (Feb. 19-March 20).