Western and Chinese Astrology

Western astrology was developed long after Chinese Astrology, and was brought to ancient Greece by the Arabs.  Initially based upon lunar cycles, astrology in the West was later developed around the solar calendar when this was first introduced by Julius Caesar around 50 BC.  Although the Julian calendar did not last long (it was replaced by the Gregorian calendar that is still in use today), Western astrologers then started to codify characteristics by reference to the twelve months of the solar calendar, whilst maintaining the importance of the lunar cycle.

Although the twelve Sun signs (or Star signs as they are often called) are approximately one month long, their start and end days owe more to the start of the Spring Equinox and subsequent phases of the moon.  To make matters worse, the day on which the Sun enters a particular sign can vary from one year to the next, and hence the Gregorian calendar needs to correct itself periodically by inserting an extra day into February.

The table below sets out the twelve Sun signs with their approximate start and end dates:

Name Sun sign Dates
Aries
21st March to 20th April
Taurus
21st April to 21st May
Gemini
22nd May to 22nd June
Cancer
23rd June to 23rd July
Leo
24th July to 23rd August
Virgo
24th August to 23rd September
Libra
24th September to 23rd October
Scorpio
24th October to 22nd November
Sagittarius
23rd November to 21st December
Capricorn
22nd December to 20th January
Aquarius
21st January to 20th February
Pisces
21st February to 20th March

When, for example, someone says that their sign is Aquarius, what they mean is that at the time of their birth the Sun was in Aquarius. Equally if not more important for relationship analysis, is the position of the Moon at the time of their birth.  At a minimum, everyone should know their Sun sign and their Moon sign, without which they cannot start to judge compatibility.