Secondary progressions read the sky one day after your birth as a picture of your first year of life, two days after as your second year, and so on. The tool gives your progressed Sun, Moon, Mercury, Venus and Mars for any date, the progressed lunar phase, the dates your progressed Moon changes sign over the next 30 years and the dates your progressed Sun changes sign in a lifetime.
How it works
The rule is one day for one year. For the date you choose, the tool counts the years since your birth, using the tropical year of 365.24219 days, and casts a chart for that many days after your birth moment. If you are 30.5 years old, the progressed chart is the sky 30.5 days after you were born. Positions come from NASA JPL DE440 data in the tropical zodiac.
To find when the progressed Moon changes sign, the tool finds the moment the real Moon changed sign in the days after your birth and turns each one back into a calendar date by the same rule. The progressed lunar phase is the angle between the progressed Moon and the progressed Sun, and its turning points (progressed new moon, first quarter, full moon and last quarter) are found the same way.
Reading the result
The progressed Moon is the part most readers start with. It changes sign every two to two and a half years, and each sign is read as the emotional focus of that chapter of life. The progressed Sun moves about one degree a year and changes sign roughly every thirty years, which is read as a slow change in where your sense of purpose is heading.
The progressed lunar phase makes one full cycle in about twenty-nine and a half years. This reading comes from Dane Rudhyar, who sets out the progressed lunation cycle in The Astrology of Transformation (1980, chapter 8) and points to his book The Lunation Cycle for the details: he reads each progressed new moon as the start of a new phase of personal growth, and the progressed full moon, about fifteen years later, as a particularly important point in it. Mercury, Venus and Mars are shown too; a change of sign or direction in any of them is read as a slow shift in thinking, relating or drive.
Where traditions differ
The day-for-a-year measure is usually traced to the 17th century astrologer Placidus de Titis, who timed his directions by allowing a year of life for each day after birth. Alan Leo’s book The Progressed Horoscope (1906) set the method out at length and did much to spread it among English-speaking astrologers. This tool counts a year of life as one tropical year of 365.24219 days; counting 365.25 days instead would move the dates by less than a day over 100 years. Astrologers move the progressed Ascendant and Midheaven by several competing methods, and those points depend heavily on the exact birth minute, so the tool leaves them out rather than pick one silently.
What it does not do
It does not predict events. It does not show the progressed Ascendant, Midheaven or houses. It also leaves out the slower planets: in our checks for births from 1900 to 2074, Jupiter moves at most about 23 degrees in 100 years of progressions (about 10 for a typical birth date) and Saturn at most about 12 (about 6), while Uranus, Neptune and Pluto move less than 6, so the tool keeps to the faster bodies. Without a birth time it uses 12:00, and every hour of difference moves the progressed dates by about 15 days, so the Moon’s dates can be up to about six months out.
Frequently asked questions
↳ What are secondary progressions?
A symbolic way of moving a birth chart forward in time, in which each day after birth stands for one year of life. The chart for your 30th day stands for your 30th year.
↳ How often does the progressed Moon change sign?
About every two to two and a half years, because the real Moon moves through a sign in two to two and a half days. The tool lists the exact dates for the next 30 years.
↳ Do I need my birth time?
It helps a lot. The progressed Moon moves fast, so each hour of error in the birth time moves its dates by about 15 days. The progressed Sun barely changes, so its sign is reliable even without a time.
↳ What is the difference between progressions and transits?
Transits are the planets in today's real sky measured against your birth chart. Progressions are symbolic: they move the birth chart itself forward at one day for each year. Many astrologers read the two together; our transits tool lists the year's transits.
↳ Why is my progressed Sun in a different sign from my Sun sign?
Because it has moved on about one degree for each year of your life. If your Sun was late in its sign at birth, the progressed Sun may already have reached the next sign. Your Sun sign at birth does not change.