This is actually a more complicated problem than it first appears.
Southern Hemisphere and Northern Hemisphere have different seasons due to Earth tilt, experience different stars (inc. 'upside down' constellations) and the Zodiacal signs reflect Northern Seasons and temperatures where Christmas, ice and winter in the NH, are experienced as high summer, heat and fireflood in, at least, Australia. Moreover, the Zodiac is entering the Age of Aquarius in the NH.
If you try to reverse it, the Zodiac becomes unworkable, because it was not designed universally, but relatively and oriented to the NH experience. You also create an Age of Virgo - and this introduces a whole new paradigm of Time, that destroys the concept of a singular Age. In short, you can reverse the NH Zodiac and accept its shortcomings to reflect the SH experience, but it doesn't, and in trying to create two Zodiacs you realise it tears the whole thing apart*.
We preferred significant alteration to make practical, functional, useable, seasonal, light-based, time-based, magical sense. We fixed the issue for ourselves by creating the Duodiac, a single device with a double wheel that fuses the incompatibilities of Astronomy and Astrology, and is suited to our Southern Climate. It restores the missing 13th Astrological sign Ophiuchus and supplies Zodiacal Relativity to one's location including alignment with the seasons.
'The way the 12-Sign Zodiac works (in Traditional Western Astrology / TA) is that the zodiac is based on dividing the 360° ecliptic (Sun’s path) into 12 equal parts of 30° each. Each part aligns (roughly) with a calendar month, though imperfectly. This has nothing to do with the real star constellations - it's a symbolic, mathematical system. In the 12-sign system, each zodiac sign = 30° of the sky = 1/12 of a year or approximately 1 month. Adding an extra house would either change each house to 28 days or extend the calendar year to 395 days, both options causing considerable
disruption. Meanwhile, the 13th constellation known as Ophiuchus (Serpent-Bearer) has traditionally been excluded despite being a real zodiacal constellation that the Sun passes through (Nov 29–Dec 17) because its inclusion would interfere in this neat arrangement of Time. This conflict raised the key question: should signs reflect actual time spent (Sidereal/Vedic Astrology) or be made equal-length for convention and practicality (Tropical Astrology)? 13ism's solution is to represent both. Therein, 13ism reflects real solar movement through actual sky constellations and includes both tropical and sidereal astrology in one diagram simply by using two separate wheels, one inside the other.'
'For THEM a critical element of Paganism is a wordless knowing that we come from the stars, and value placed on having gratitude and respect and an ability to recognise and flow with the changes of the land that affect and influence our organism and human endeavours. For us, paganism is a human connection with the land where both human and land are viewed as extensions of an identical source of nature and its changes. Given that THEM is an Australian Magickal Order, to honour what we observe in the stars and in the land an organic representation of the elements is required that reflects our SH experience so we felt it necessary to either remedy this significant gap in Australian paganism - or at least begin re-raising and addressing the issue. The purpose of this reworking is straightforward and derives from a simple premise. Namely, if we are to work sympathetic magic to explore - or acknowledge - the influence of the celestial spheres, stars and other wonders of the world either in the changes observed in nature via our unique seasonal alchemy or applicable to personal psychology (expanded by Carl Jung), then surely, we must flow with these forms and forces in a proper attunement as they occur. We have subsequently devised a New Wheel called the Duodiac - a hybrid system that balances symbolic harmony with astronomical truth fusing Tropical (typical) Astrology (shown on an Inner Wheel), with Sidereal (Vedic) Astronomy (shown on an Outer Wheel) like a watch with two faces.
We have also developed Thirteenism (13ism) an approach to Astrology-Astronomy (Astrae) which re-includes the 13th constellation of Ophiuchus without disrupting the traditional 12 house system of the Zodiac and allowing others to import tropical astrology effortlessly. We have replaced the NH celebrations with our own event names and times to reflect our real-world experience and needs here in Australia, have assessed the Sun's path for us requires a reversal of NH deosil and widdershins, have included other important astronomical features including the lunar houses, daylight savings times, the analemma, perihelion/aphelion, annual meteor showers (given that Victoria is fortunate to have a dark sky experience) and have revised how seasons are visually represented. To signify 13isms wheel as a Southern Hemisphere device, it features an icon for Sigma Octantis, the Southern Celestial Polestar, at its heart. The top of the diagram as it appears on screen or paper should not be interpreted as ‘North’, nor assumed to be aligned with the depicted West–East Sun-path circle, which functions as a separate observer-relative guide. The placement of the Vernal Equinox at the top reflects its conventional role as the beginning of the seasonal cycle, and as the eye tends to travel from top-down, is placed there for convenience with the Duodiac arranged in a counter-clockwise design.' - p. 473. The Corpus Themeticum by the Temple of THEM.
*If for instance, you invert the NH model to an SH model and create a mirror-image of the thing, you fit two hemispheres together rotated at 180 degrees to one another, but accidentally create an Age of Virgo, since the SH is still beholden to the precession of the Equinox, and must then ask what do the people in the division between these spheres experience on the Equator line? Is there then a third Age, and so on which detonates Astrology because it's premised on a single simple (relative) approximation of Time claiming universality.
