The Zodiac
The 12 “star signs” the astrologers use are the constellations that fall on the ecliptic, otherwise referred to as the zodiac. The ecliptic is merely the path the sun seems to follow as the earth revolves around it. So, if on a certain date you looked at the sun, the current “star sign” would be the constellation directly behind the Sun.
Star Sign (Constellation).............Date
Sagittarius........................Nov 22 Dec 21
Capricornus.......................Dec 22 Jan 19
Aquarius...........................Jan 20 Feb 18
Pisces..............................Feb 19 Mar 20
Aries................................Mar 21 Apr 19
Taurus.............................Apr 20 May 20
Gemini..............................May 21 Jun 21
Cancer.............................Jun 22 Jul 22
Leo..................................Jul 23 Aug 22
Virgo................................Aug 23 Sep 22
Libra................................Sep 23 Oct 22
Scorpius...........................Oct 23 Nov 21
The zodiac is “A belt on the celestial sphere, about 8° either side of the ecliptic, which forms the background for the motions of the Sun, Moon, and planets.” The ecliptic passes through more than 12 constellations, it passes through 13, the thirteenth being Ophiuchus. Why do the astrologers ignore poor old Ophiuchus? Probably because it is not a particularly bright constellation. But that does not change the fact that the ecliptic passes through 13 constellations, not 12.
Star Sign (Constellation)..............Date
Sagittarius.........................Dec 18 Jan 18
Capricornus........................Jan 19 Feb 15
Aquarius............................Feb 16 Mar 11
Pisces...............................Mar 12 Apr 18
Aries.................................Apr 19 May 13
Taurus..............................May 14 Jun 19
Gemini...............................Jun 20 Jul 20
Cancer..............................Jul 21 Aug 09
Leo...................................Aug 10 Sep 15
Virgo.................................Sep 16 Oct 30
Libra.................................Oct 31 Nov 22
Scorpius............................Nov 23 Nov 29
Ophiuchus..........................Nov 30 Dec 17
http://www.aqua.co.za/assa_jhb/Canopus/c979zodi.htm