Your Solar Arc timeline.

Solar Arc is a predictive technique developed in the modern Western tradition: every chart point — planet, angle, lot — is moved forward at the rate of the Sun's daily motion (about 1° per year). Year 30 of life sees every body in your chart 30° further along the zodiac. Contacts perfect when a directed body comes within orb of a natal placement. The technique surfaces life-shaping events with remarkable precision when the natal chart has tight, exact placements.

Secondary progressions move every body at its actual ephemeris speed, day-for-a-year — so the Moon shifts ~13° per year (the fast inner clock) while Pluto barely moves. Solar Arc moves everything together at the Sun's rate, so the relative positions stay locked, but every body's aspect to natal placements perfects on a slower, more ordered timeline. Progressions are favored for inner/emotional development; Solar Arc for structural, event-shaping arcs.

Naibod-via-Sun (the default here) is the modern standard — it uses the natal Sun's exact daily speed at birth, which respects each chart's specific Sun. Naibod (mean) uses a fixed 0.9856°/year; the difference is small. Ptolemy (1°/year) is the classical hand-calculation rule and gives slightly different perfection ages. Kepler scales by 365.25 days. Default to naibod-via-sun unless you have a specific tradition in mind.

Converse directions flip the arc backwards in time — every chart point moves the same distance, but in the opposite zodiacal direction. Used for the symbolic shadow-time read: what would have happened if the chart had been read in reverse. Some practitioners pair direct + converse for a complete predictive picture; others ignore converse entirely. Default off; turn on when your tradition uses it.

Look for clusters: ages where multiple Solar Arc contacts land within a few years tend to be life-restructuring windows. Pay particular attention to outer-planet directed contacts (Saturn, Uranus, Neptune, Pluto) to natal Sun, Moon, Ascendant, or Midheaven — these mark major identity-shaping years. Then layer your transit forecast and progressed Moon to time when the structure actually fires.

It tends to be remarkably accurate when read across decades, less precise for the timing of any single event within the year of perfection. Tradition holds the year before, year of, and year after the exact perfection are all in the active window. For finer timing, layer with current transits.