Hank Friedman on his Learn Astrology Free site. has this general check of software based on information he obtained from Dr. Myles Standish of Yale University, New Haven, Connecticut. This became an issue for me recently because of the poet Dante Alighieri’s chart, mentioned by Dr. Marc Jones in his Guide to Horoscope Interpretation, that created disparate charts in Janus & Kepler.

That really bothered me, and I remembered Hank had something on it when I trying out Janus 5.0 as a test for astrology software, so I dug up the post. I will post the Dante issue under Dante’s essay.

Hank Friedman’s general test of software accuracy

For January 1, 01 AD (Julian date) at Midnight in Greenwich, England:

  • Ascendant 5 Libra 50
    • Sun 9 Capricorn 22
  • Moon 13 Leo (different programs vary from 12 Leo 55 to 13 Leo 13)
    • Mercury 14 Capricorn 25
  • Venus 25 Aquarius 10
    • Mars 11′ Aries 0″
  • Jupiter 9 Libra 7
    • Saturn 11 Gemini 19 R
  • Uranus 26 Pisces 14
    • Neptune 19 Scorpio 40 (plus or minus one or two minutes)
  • Pluto 27 Virgo 29′
    • True Node 29 Sagittarius 01″ to 04″

I did not input the asteroids and test their exactness, because they do not really matter with my work. Instead, I use “orbs” to overcome mathematical errors at that level. Therefore, I increased Mr. John Addey’s recommended orbs a bit {which I use in tandem with Mr. Vivian Robson’s 1 specified in Robson’s A Beginner’s Guide to Practical Astrology, published 1931, London} typically a half a degree, because I do not know what software, if any, he used, and I found I was missing a lot of aspects.

The charts on the new site, Celestiology, use Mr. Robson’s orbs and the original Sabian Ptolemaic aspects are slowly being deprecated.

Hellenistic Orbs vs Modern

Traditionally, to avoid the orb issue, Hellenistic astrologers use whole houses, and make one whole house in aspect to another. Modern astrologers like Marc Edmund Jones and C. C. Zain, use Translation of Light to create the same effect. Software btw does not not have an accounting for ToL so that is something the astrologer must manually account for unless as I originally did on the Sabian Earth site and use the large Ptolemaic orbs.

What software I tested

I could only test Janus 5.0 and Kepler because I no longer have Solar Fire 9.0. Somewhere along the line my software got corrupted and does not install properly and to fix the error, SF required an upgrade fee; I did not pay, and that ended that. Perhaps one day I will, I cannot at this point say.

Kepler and Friedman’s Test of Accuracy

Below is the output from Kepler Software, produced by David and Fei Cochrane in Gainesville, Florida. The red arrows show what is off by at least a degree, I did not care about minutes as the orb or rounding for Symbols will take care of that. Friedman of course does not have listed the Midheaven nor the Part of Fortune, both of which are on the Kepler report.

Kepler has Aquarius for the Part of Fortune and Janus Taurus because on Kepler I chose always use the Day or Modern Formula, while on Janus I chose to use the Night for Night and the Day for Day or the Ancient formula.

I chose the format of Whole or Natural Houses so that everything could be plainly compared. All the arrows on the Kepler map are the 1 degree or greater variation from the Friedman ephemeris, including, and this was a genuine surprise, the Ascendant. I rarely have a chart to note the difference in ascendant from the data in Jones Sabian Symbols, so I have never paid much attention to the difference in time and ascendant.

This disparity bothers me so I think I need to check it out further, but honestly I do not think Kepler will be off on modern charts otherwise when doing the two in Janus and it I would have noticed the difference. I think the problem is in charts greater than perhaps 200 years; Dante’s chart is over 650 years ago, and obviously Kepler’s ephemeral accuracy does not span that far back. How much that matters depends upon how much astrological historical research you do.

To prove that, Friedman has another test for January 1, 2050, in London, which I will do next.

Janus 5.0 and Friedman’s Test of Accuracy

No surprise that the New Zealand Janus matched Friedman’s test because, as I previously mentioned, I tested that before purchase. Things are off by minutes but again that is ignored by orbs, hence why I do not use one degree orbs even on the 1 degree chart but one and half degrees.



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