What a secondary progression is

It is the sky of the first days of your life, read one day per year. Someone turning thirty has the chart of the thirtieth day after their own birth; someone turning fifty, of the fiftieth. What changed in the sky over those few days is what the technique reads as the arc of a whole life.

It sounds arbitrary and it is not: the equivalence between a day and a year is one of the oldest measures in astrology, and it exists because the two cycles are the sky's two clocks — the Earth turning on itself and the Earth going round the Sun. What the progression does is fit one into the other.

And it is not the sky of today. Two people turning thirty today have different progressions, because each has her own thirtieth day. That is why the technique describes an inner time and not a general climate.

How far each point travels per year of life

The arithmetic is direct: how far the planet travels in one day is how far it travels in one year of life. The averages below were measured with the same ephemeris this site uses to build charts, day by day, from 1930 to 2030:

Look at the first three rows, because they explain the whole technique. The Moon is the only fast hand; the Sun is the slow one; and from the middle of the table down the planets barely leave their place. A progression is not the whole chart moving: it is two points moving over a chart that is almost still.

Mercury and Venus travel with the Sun, and that is no coincidence

The three averages are the same: 0.985, 0.986 and 0.986 degree a day. It is not rounding — it is orbit. Mercury and Venus go round the Sun, so, seen from the Earth, they keep the Sun company all year: Mercury never gets more than 28 degrees away from it and Venus never more than 48.

In a progression that has a practical consequence almost no text mentions: progressed Mercury and Venus change sign more or less when the progressed Sun changes, give or take a few years. Anyone expecting “progressed Venus entering Libra” as an independent event is expecting something that walks hand in hand with the Sun.

The progressed Moon is the hand you can date things by

It closes the circle in 27.3 years and stays about 2.3 years in each sign. Measured: the Moon's speed in the sky varies from 11.77 to 15.35 degrees a day, so one progressed sign lasts from 1.95 to 2.55 years — the variation belongs to the Moon, not to the technique.

That is why the progressed Moon is what astrologers use to mark a period. It is fast enough to change inside one phase of a life and slow enough not to change every week, which is the problem with the real transit of the Moon.

And the 27.3-year circle has an echo: it is almost the same thing as the Saturn return, which happens around the age of twenty-nine and a half. Two independent calculations landing in the same decade of life — and one of the reasons that period is so talked about.

The progressed Sun changes sign once, and the age depends on the degree

It takes 30.4 years to change sign. Since everybody is born with the Sun somewhere between 0 and 30 degrees of a sign, the age of the first change is the distance left divided by one degree a year: those born at the start of a sign change close to thirty, and those born at the end change in childhood. The average is 15.2 years.

And there is a difference that comes from the calendar: the Earth runs closer to the Sun in January than in July, so the Sun appears to move faster. Measured: 1.020 degrees a day on 6 January and 0.953 on 11 July. Someone born in January has a progressed Sun 7% faster than someone born in July — and, by the end of a life, that comes to two years of difference in the age of the changes.

The progressed New Moon comes back every 29.5 years — and it is the lunar month in years

Put the two hands together and the prettiest cycle in the technique appears. The progressed Moon moves 13.176 degrees a year and the progressed Sun moves 0.986: the difference between them is 12.19 degrees a year. For the Moon to catch the Sun again — to gain a whole turn on it — 360 degrees have to be covered, which gives 29.5 years.

It is the same 29.5 as the lunar month, which lasts 29.5 DAYS. It is neither coincidence nor poetry: it is the same arithmetic with the unit swapped — one day for one year, which has been this technique's ruler since the first line of this page.

In practice that divides a life into eight phases, the way the phases of the Moon divide the month: the progressed New Moon around 0, 29 and 59, the progressed Full Moon some fifteen years after each one. Anyone wanting to check the technique against their own life has here the most honest test it allows — and it does not depend on believing anything: it is arithmetic with dates.

How to read a progression without getting lost

The practical rule fits in four lines, and it comes straight out of the table above:

• Start with the progressed Moon. Which sign and which house it is in now, and when it changes. It is the only hand that moves inside one phase of a life.
• Then the progressed Sun. If it changed sign in the last few years, you have a long arc under way — and that happens once or twice in a whole life.
• Look at the aspects that form, not at the positions. What a progression has that can be dated is the moment a progressed point touches a point of the natal chart.
• Ignore what has not moved. Progressed Saturn at 0.033 degree a year is not the subject of a year; it is the same Saturn from the cradle, under another name.

What gets confused with progression, and is not

• Transit. It is the sky of TODAY passing over your chart, the same for everybody on the same day. A progression runs from your birth and does not look at where the planets are now.
• Solar arc. It is also a progression, with another ruler: instead of each point moving at its own speed, the WHOLE chart moves as far as the progressed Sun moved. That is why, in the solar arc, Pluto “moves” a degree a year — and in the secondary progression it does not leave its place.
• Solar return. It is the chart of the instant when the Sun comes back to the exact degree it was born in, once a year. It has nothing to do with the day-for-a-year equivalence; the subject is in solar return.

What a progression does not answer

It does not mark the date of an event, and no technique in this house does. A progression describes an arc — a stretch in which a subject matures — and its ruler is measured in years, not days. Anyone promising the exact day is promising what the arithmetic does not give.

And there is an arithmetic limit worth saying out loud: the slow planets barely move, and sometimes go backwards. Measured across a hundred years of birth dates: over ninety years of life, the progressed Jupiter of someone born on 24 October 2024 goes back 9.4 degrees, and that of someone born on 4 February 1975 advances 21.2. A reading that makes “progressed Pluto” the subject of a year is reading a point that has moved less than half a degree since the cradle.

And the usual limit, which is part of reading seriously: astrology does not predict events, does not diagnose anyone and does not decide for anyone. These are tendencies, and a tendency is something you work with.

Frequently asked questions about progressions