More than once I've tossed an idea around, in my head, that it would be possible to create a plausible secondary, and simpler, zodiac based on the broad concept of seasonal astrology, with some additional detail culled from standard tropical astrology. The seasonal zodiac would rely primarily on the four angles, ascendant/descendant & midheaven/nadir. Fewer zodiac signs created by fusion of two or more of the traditional signs might create the seasonal zodiac circle. But, then again, maybe this is just my own Aquarius Sun trying to cause chaos!
Positions and aspects between Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn are thought by astrologers to have varying levels of reflection in our individual personality traits. The outer and slower-moving planets, Uranus, Neptune and Pluto are thought to connect more to generations, unless closely linked to one of the faster-moving planets natally, or in transit.
Quite often at least six of the seven faster-moving bodies (Moon is excluded because of its even faster motion) lie within one half of the zodiac circle. Mercury and Venus, for example are never further from the Sun than the space of two signs, often less than that. When planetary emphasis is concentrated in roughly half of the zodiac signs, in theory personality traits of people born with Sun among the involved signs are likely to have more broad compatibility with each other than with people born in the other half of the zodiac. I say "broad", because other complications and considerations are involved - rising signs and Moon position among them. This idea might be relevant to the experience of the guy mentioned above, whose children and others with whom he'd had close relationships had birthdays in the first half of the year.
I took a look at my own natal chart, and, stripping away the outer planets and Chiron the faster planets and Moon all lie between Aries and 28 degrees Scorpio. So, though I usually say I have a "splash" chart, that is only due to the generational planets. I'm a Winter-to-Spring person.
All this relates only to the northern hemisphere. What about people born in the southern hemisphere? There'd be a different seasonal zodiac for them.
Terence Guardino in "The Seasons of Astrology" explained his own version.
From Amazon's page on the book
The Seasons of Astrology: How Your Biological Clock is the Link to Your Sun Sign Personality explains how the apparent rising and setting of the sun influences our personalities as well as the seasons. The amount of light versus darkness during the month one is born begins to imprint the personality of each sign. The amount of light versus darkness also begins to imprint each of our individual biological clocks during infancy.
The light relates to our personal ego needs as separate individuals needing to be expressed out into the world. The sun signs born with equal light and darkness are Aries and Libra but the signs with more light during the day than darkness are Taurus, Gemini, Cancer, Leo and Virgo as they strive to be noticed. The dark relates to all the collective needs of the group rather than the individual. The dark represents society, government, laws, organized religion and community. The signs with more darkness than light when born focuses their attention more on community rather than the individual are Scorpio, Sagittarius, Capricorn, Aquarius and Pisces.
Capricorn begins at the Winter Solstice when the day has the shortest amount of light. Thus Capricorns are more inclined to pull inward to feel safe and be more serious. Aquarius begins to have a little more light and 'lightness' but still with long winter nights. Aries begins the Spring Equinox with an equal balance of daylight and darkness but the next sign Taurus has a bit more light during the day giving more confidence to express itself in the world and so forth with each sign until you arrive at Scorpio when there is more darkness than light. Scorpio is known for being mysterious, secretive, hard to get to know but also insightful and powerful.