Begin with the recorded birth moment
A local birth date and clock time need a historical UTC offset before they identify one astronomical instant. Enter the offset that was actually in force, including any summer-time adjustment. For example, a recorded 12:00 local time at UTC+2 becomes 10:00 UTC. Every planetary longitude is then calculated for that UTC moment. This planetary comparison does not request coordinates and intentionally omits axes and houses. A precise birth time should come from a record, not a guess; the Moon moves fast enough that a guessed clock hour can make a close comparison misleading.
The secondary progressed layer
Secondary progression maps each tropical year of age to one ephemeris day following birth. This site uses 365.24219 days for one tropical year. At exactly 30 such years after birth, it inspects the sky exactly 30 days after the natal instant. At 30.5 years, it inspects 30.5 days after birth. The resulting positions are astronomically calculated for that symbolic ephemeris moment, then displayed in relation to the natal zodiac. They are not the planetary sky on the life date. The progressed Moon changes much faster across life years than most other progressed bodies, so check the recorded birth time and the selected target UTC hour before treating a narrow contact as exact.
The true solar arc layer
Solar arc direction starts with the Sun’s movement from its natal position to its secondary progressed position. Express both as tropical ecliptic longitudes and subtract the natal Sun from the progressed Sun, wrapping at 360°. Add the resulting arc to every natal planet. For a simple arithmetic example, a natal Sun at 29° of a sign and a progressed Sun at 1° of the next sign produce a 2° forward arc, not a 28° backward arc. Every directed planet receives that same 2° arc. The directed Sun is consequently identical to the secondary progressed Sun. The directed Moon generally is not the secondary progressed Moon: the first shifts its natal longitude by the Sun’s arc, while the second uses the Moon’s own ephemeris movement.
A mean solar arc is another documented choice. It multiplies elapsed years by an average Sun key, commonly the Naibod value 0.98564733° per year. This combined page chooses the true arc from the calculated progressed Sun. The site's solar arc comparison shows both methods. Results may also differ from other providers because of ephemeris choices, time conversion, rounding, and angle conventions. The method label should travel with any saved result.
What the wheel and tables show
The center ring is natal, the middle ring is the secondary progressed chart, and the outer ring is the true solar arc direction. Each ring contains the ten named planetary points. If symbols overlap in a narrow zodiac area, read their tooltips and the numerical table, which gives every displayed point to hundredths of a degree. Separate aspect tables compare each moving layer to natal planets using conjunction, sextile, square, trine, and opposition, each within one degree. An aspect list is a geometry filter; it does not prove an event or guarantee an interpretation.
Angles and houses are excluded. Adding an ecliptic solar arc to a natal Ascendant is a different construction from recalculating an Ascendant at a directed sidereal time. This page avoids presenting either as a universal default. A reader who needs angle work should first settle the birth time and explicitly choose a convention.