The crux of the zodiac confusion goes back to the source of Horoscopic astrology. Anyone who has studied the recent translations of Project Hindsight, ARHAT and other translators realizes that the evidence is powerful for Horoscopic astrology originating in the west at a time when Helleisitic astrologers weren't sure what zodiac they were using. I know the arguments rage on about India being the oldest source of Horoscopic astrology, but the evidence is otherwise.
Much that is in India's so-called ancient texts most probably came from translated Hellenistic and Arabic texts. So naturally there are going to be many statements related to the tropical zodiac, the seasons, etc. because these texts are post-Ptolemy,
I clearly remember the day when I realized that the texts of the ‘great Indian sages' were mostly translations of western texts. Or, if not direct translations, the astrological concepts were clearly western. My entire devotion to the sacred astrology of India's sages came tumbling down. Since my recovery from the shock, I've carefully followed the Hellenistic translation work currently being done, especially Project Hindsight translations.
However, most astrologers don't realize that *western* astrologers continued using a sidereal zodiac (imported from Mesopoamia) until the 5th century. Check out this web site http://www.phys.uu.nl/~vgent/babylon/ba ... dstars.htm
which has a diagram (at the end of the list of references, approximately page 20) of the actual sidereal longitudes in horoscopes compared to the tropical longitudes. Quoting from the web site:
"Although Hellenistic astronomers based their measurements and theories on a tropical zodiac..., Hellenistic astrological tables and horoscopes indicate that the sidereal zodiac was employed up to the end of the 5th century AD..."
"Studies of luni-solar and planetary longitudes mentioned in Late-Babylonian horoscopes and diaries have revealed that they are always measured from a fixed position with respect to the stars and are therefore based on a sidereal zodiac. The use of a sidereal zodiac was continued by many astrologers of the Hellenistic and Roman Period.
"The following diagram, based on the data in Kollerstrom (2001), plots the longitude offsets as found in Late Babylonian horoscopes (purple data points) and Greek horoscopes (blue data points) with respect to the tropical zodiac. The slope of the weighed least-squares fit through the data is equivalent with a longitude shift of one degree in 75.4 years. Around the year AD 307 the astrologers' sidereal zodiac coincided with the tropical."
We don't know how or why India's astrologers remained with a sidereal zodiac while the west settled on the tropical zodiac. If India really did have enlightened astrological sages, then they were responsible for keeping the sidereal zodiac as their working zodiac.
I know that mathematically the sidereal zodiac checks out for transits and solar returns. I'll be posting some examples here as soon as possible. One cannot argue about how exact transits are, but there are many different ways to read solar return charts, so I'll begin with event transits to natal charts.