What is the Allan Leo Progression?
Allan Leo's "day-for-a-year" progression is a predictive technique where each day after birth represents one year of life. The planetary positions on day 42 after birth, for example, describe the events and energies of your 42nd year.
A 120-day ephemeris from your birth date produces a complete 120-year life map.
The Dynamic Natal Chart Concept
In our Modified Method, the natal chart is not static. It updates over the 120-year progression based on planetary motion changes. This is called the Dynamic Natal Chart.
The Dynamic Natal Chart is then compared against the raw progressed ephemeris (original day-Y positions) to find aspects.
Year_Score = sum( all aspect finalScores )
Rule 1 — Freeze Inner Planets & Houses
Action: Lock Sun, Moon, Rahu, Ketu, and all 12 house cusps (including Ascendant and Midheaven) to their natal (Day 0) positions for every progressed year.
| Frozen to Natal (Day 0) | Free to Progress (Rule 2) |
|---|---|
| Sun, Moon, Rahu, Ketu | Mars, Mercury, Venus |
| Houses 1-12, Ascendant, Midheaven | Jupiter, Saturn, Uranus |
Why freeze these?
- Moon moves ~12-14° per day — in 120 days it traverses the zodiac 4+ times. Meaningless for yearly analysis.
- Sun moves ~1° per day — only 120° total. Not sufficient for meaningful yearly shifts.
- Rahu/Ketu are shadow planets (lunar nodes) — their position is used as a reference for Effective Retro Status, so they must stay fixed.
- Houses depend on exact time within a day — doesn't scale to years.
Rule 2 — Motion-Change Progression
This is the core of the Modified Method. Planets are divided into two categories with different behaviors:
Fast Planets: Mars, Mercury, Venus
| Motion State | What Happens |
|---|---|
| Direct (same as reference) | Freeze at reference degree |
| Retrograde (same as reference) | Update to progressed degree |
| Motion changed (D→R or R→D) | Current position becomes new reference. Update degree. |
Slow Planets: Jupiter, Saturn, Uranus
| Motion State | What Happens |
|---|---|
| Any motion | Always update to progressed degree |
Example — Mercury (natal 11° Cancer, Direct)
| Age | Ephemeris | Motion | Action | Degree Used |
|---|---|---|---|---|
| 0 | 11° Cn | D | Natal | 11° Cn |
| 30 | 25° Cn | D (same) | Freeze at reference | 11° Cn |
| 42 | 1° Le | R (changed!) | New ref = 1° Le, Update | 1° Le |
| 43 | 29° Cn | R (same) | Update (retrograde) | 29° Cn |
| 44 | 28° Cn | R (same) | Update (retrograde) | 28° Cn |
| 55 | 20° Cn | D (changed!) | New ref = 20° Cn | 20° Cn |
| 56 | 21° Cn | D (same) | Freeze at reference | 20° Cn |
Effective Retrograde Status (EffR)
The raw retrograde status (D/R from ephemeris) is not always the true picture. The Effective Retrograde Status applies Vedic nakshatra analysis to determine the real functional status of each planet.
| # | Condition | EffR Result | Explanation |
|---|---|---|---|
| 1 | Own Star (planet in its own nakshatra) | D (always) | Self-empowered planet — always functions as Direct |
| 2 | Direct motion (no Ra/Ke connection) | D | Normal direct motion |
| 3 | Retrograde motion (no Ra/Ke connection) | R | Normal retrograde motion |
| 4 | Direct + Rahu/Ketu star connection | R (flipped!) | Nodes invert the planet's nature |
| 5 | Retrograde + Rahu/Ketu star connection | D (flipped!) | Double inversion = functionally Direct |
What is a Rahu/Ketu Star Connection?
A planet has a Ra/Ke connection if:
- The planet's nakshatra is the same as Rahu's or Ketu's nakshatra, OR
- The planet's nakshatra lord is the same as Rahu's or Ketu's nakshatra lord
Rahu/Ketu positions are always taken from the natal chart (frozen by Rule 1).
Which Nakshatra Position to Use?
| Planet State | Nakshatra From |
|---|---|
| Frozen at natal degree (Direct fast planet) | Natal nakshatra |
| Retrograde / Updated position | Current progressed nakshatra |
Aspect Scoring — Sign Multiplication
The final score for each aspect is determined by multiplying three signs together:
Where: D = + (positive) R = - (negative)
Aspect Type Classification
| Aspect | Angle | Sign | Condition |
|---|---|---|---|
| Conjunction | 0° | + | Benefic × Benefic (Asc, MC, Su, Mo, Me, Ju, Ve) |
| Conjunction | 0° | - | Malefic × Malefic (Ma, Sa, Ur) OR Benefic × Malefic |
| Sextile | 60° | + | Always positive |
| Trine | 120° | + | Always positive |
| Square | 90° | - | Always negative |
| Opposition | 180° | - | Always negative |
Planet Weights
| Planet | Weight | Planet | Weight |
|---|---|---|---|
| Midheaven (X) | 14 | Jupiter | 5 |
| Ascendant | 10 | Sun, Moon, Mars | 4 |
| Uranus | 7 | Mercury, Venus | 2 |
| Saturn | 6 | Rahu, Ketu | 5 |
Weighted Score = (Weight of planet 1 + Weight of planet 2) × base score of aspect type
Orb Settings
| Direction | Default Orb | Meaning |
|---|---|---|
| Approaching (negative orb) | 1.5° | Progressed planet moving toward exact aspect — wider tolerance |
| Separating (positive orb) | 1.2° | Progressed planet moving away from exact — tighter tolerance |
Scoring Examples
| Natal | EffR | Progressed | EffR | Aspect | Type | Calculation | Result |
|---|---|---|---|---|---|---|---|
| Jupiter | D(+) | Venus | D(+) | trine | + | + × + × + | Positive |
| Midheaven | D(+) | Mercury | R(-) | trine | + | + × - × + | Negative |
| Sun | D(+) | Mars | D(+) | square | - | + × + × - | Negative |
| Saturn | R(-) | Mercury | D(+) | sextile | + | - × + × + | Negative |
| Mars | R(-) | Saturn natal | R(-) | trine | + | - × - × + | Positive (double negative!) |
| Mars | R(-) | Venus | D(+) | square | - | - × + × - | Positive (double negative!) |
Aspect Comparison — What Compares Against What?
Not all planets participate in aspect comparison. The roles are clearly defined:
| Side | Planets Included | Source |
|---|---|---|
| Natal (receivers) | Su, Mo, Ma, Me, Ju, Ve, Sa, Ur, Asc, X | Dynamic Natal Chart (Rule 1 + Rule 2 applied) |
| Progressed (actors) | Su, Ma, Me, Ve, Asc, X | Raw ephemeris (no rules applied) |
Key exclusions:
- Ju, Sa, Ur appear only on the natal side — they receive aspects from progressed planets but don't form aspects as progressed planets
- Moon appears only on the natal side — frozen by Rule 1, it serves as a natal reference point
- Rahu/Ketu are excluded from aspect comparison entirely — they only influence the Effective Retro Status calculation
- Same-planet aspects are skipped (e.g., natal Mercury vs progressed Mercury)
The Details Table
When you click a year bar in the graph, the aspect details table shows all the information used in scoring:
| Column | Meaning |
|---|---|
| Natal | The natal planet name |
| R | Raw retrograde status from ephemeris (D or R) |
| EffR | Effective Retro Status after 5-rule analysis (D or R) |
| Deg | Degree position (DD°MM' Sign) |
| Progressed | The progressed planet name |
| R / EffR / Deg | Same as above, for the progressed planet |
| Aspect | Type: conjunction, sextile, trine, square, opposition |
| +/- | Aspect sign: + (positive) or - (negative) |
| Orb | Angular distance from exact aspect (negative = approaching, positive = separating) |
| Base | Weighted score before EffR multiplication |
| Final | Score after sign multiplication (EffR × EffR × Aspect × |base|) |
Rows highlighted in yellow indicate a reversal — where the Final score has opposite sign from the Base score due to EffR influence.
API Reference
Server-side API that computes the complete Modified Progression. Returns 120 years of scored aspects.
Request Body
"date": "1985-06-16",
"time": "08:12:00",
"lat": 17.385,
"lon": 78.4867,
"timezone": "5.5",
"ayanamsha": "lahiri",
"method": "modified",
"orb_approaching": 1.5,
"orb_separating": 1.2,
"weights": { "SU": 4, "MO": 4, ... }
}
Response — Year Entry
"year": 2027,
"age": 42,
"score": -26,
"aspects": [
{
"natal": "10", "natalR": "D", "natalEffR": "D",
"natalDeg": "1°33' Ar",
"progressed": "ME", "progR": "R", "progEffR": "R",
"progDeg": "1°45' Le",
"aspect": "trine", "aspectSign": "+",
"orb": "0.20",
"baseScore": 80, "finalScore": -80
}
]
}
In this example, Midheaven (D+) trine Mercury (R-) with positive aspect (+) gives: + × - × + = -80
How to Use
- Open the RVA Software tool and enter birth details
- The 120-year progression computes automatically via the API
- Scroll to the Alan Leo Analysis section
- The bar chart shows year scores — green = positive, red = negative
- Use period buttons (10Y, 20Y, 60Y, All) to zoom into specific life periods
- Click any bar to see the aspect breakdown with full R, EffR, and sign multiplication details
- Yellow-highlighted rows show where EffR caused a score reversal