Secondary progressions: your chart's slow evolution
A day of sky for a year of life. The slowest clock in astrology, and the one most practitioners keep.
2 min read · Published 30 August 2026
Straight to it
Secondary progressions advance the chart one day for each year of life, so your chart at 40 is the sky as it looked 40 days after you were born. The progressed Sun moves about a degree a year, the progressed Moon about a degree a month. Practitioners watch for the progressed Sun changing sign, the progressed Moon changing sign, and the progressed New and Full Moon.
What moves
| Factor | Progressed speed | Notable event |
|---|---|---|
| Sun | About 1° per year | Sign change roughly every 30 years |
| Moon | About 1° per month | Sign change every 2.5 years; full cycle in 27–28 years |
| Mercury | Variable; can turn retrograde | A progressed station lasts years |
| Venus | Variable; can turn retrograde | As above |
| Mars | About 0.5° per year | Sign change every 50–60 years |
| Jupiter and beyond | Barely moves | Effectively fixed within a lifetime |
Only the Sun, Moon, Mercury, Venus and Mars move enough to count. Jupiter and beyond barely shift across a whole life.
Why a day for a year
The usual justification cites the day-for-a-year principle in Hebrew scripture. That explains where the idea came from, not why it should work.
A second argument notes that the Moon's 27-day cycle, progressed, becomes 27 years, close to a generation. That is reasoning backwards from a convention. The ratio was chosen because it moves things on a human timescale.
A day for a year is a beautiful idea with no reason behind it, and I say that fondly.
The events to watch
- Progressed Sun changes sign. Once every thirty years or so. The biggest event in the technique.
- Progressed New Moon. Sun and Moon conjoin, opening a 29-and-a-half-year cycle.
- Progressed Full Moon. Fifteen years later. Something begun becomes visible.
- Progressed Moon changes sign. Every two and a half years. See progressed Moon cycles.
Reading them
Compare the progressed chart against the natal one, never against itself. Orbs are one degree, because progressed factors move so slowly that a wider orb would last years.
AsterNym computes your progressed Sun, Moon and lunation phase on your natal chart, and names its method for progressed angles because others disagree.
The follow-ups
- How do secondary progressions work?
- Each day after your birth stands for one year of life, so your chart at forty is the sky forty days after you were born.
- What is the most important progression event?
- The progressed Sun changing sign, roughly once every thirty years. Then the progressed New Moon, then the progressed Moon's sign changes every two and a half years.
- Do outer planets progress?
- Barely. Jupiter and beyond move so little across a lifetime that they are effectively fixed.
Xavier Brooks