What's your sign? If today's your birthday, you're an Aries, the first constellation in the Western zodiac. Many astrologers believe that certain personality traits, physical conditions and even a person's fate and future can be influenced and determined by his zodiac sign. When zodiacal constellations were first organized, some 2,000 years ago, the Sun was in Aries where it crossed the equator at the vernal equinox, and Aries became the first sign of the zodiac. This is also the first day of the Bahá'í calendar, Chunfen in China and International Astrology Day.