What this calculator does
The chart engine first calculates a tropical Ascendant, Sun, and Moon. It derives Fortune and Spirit with sect-aware formulas, then starts a sign-by-sign timing sequence from the selected lot. Level 1 uses the traditional sign values as 360-day years. Inside the active Level 1 chapter, Level 2 uses those same values as 30-day months.
The output shows one full Level 1 zodiac circuit and every Level 2 period inside the chapter containing the focus moment. Dates are exact UTC instants. A highlighted row is active from its printed start up to, but not including, its printed end.
Why Fortune and Spirit produce different sequences
For a day chart, Fortune is Ascendant + Moon − Sun, while Spirit is Ascendant + Sun − Moon. The terms exchange for a night chart. Because the release begins from the sign of the selected lot, the two sequences commonly start in different places. Book IV connects Fortune with bodily and material circumstances and Daimon, usually called Spirit in modern English, with activity and occupation. Those are historical topic frames rather than guarantees about a person.
When the two lots land in the same sign, Book IV tells the activity sequence to begin from the following sign. The calculator applies that instruction only to a Spirit release and states when it was used. The separate Fortune and Spirit calculator shows the underlying lot arithmetic in more detail.
Boundaries and the loosing of the bond
One circuit of the twelve Level 2 allotments totals 211 months, or 17 years 7 months in the ideal calendar. Only Level 1 chapters longer than that can complete the circuit. The next Level 2 period then begins in the sign opposite the Level 1 sign and is marked “Loosing of the bond.” The last subperiod is shortened whenever its full allotment would extend beyond the parent chapter.
This tool stops at Level 2. It does not add Level 3 or Level 4 periods, degree-based variants, peak labels, natal delineations, or event forecasts. Read the method guide for a worked sequence and the calendar assumptions.
Primary text and method scope
Vettius Valens, Anthologies, Book IV, translated by Mark T. Riley describes distribution from Fortune and Daimon in chapter 4, the opposite-sign handoff in chapter 5, and the sign allotments in chapter 6. The calculator implements the chapter 4 sequence through two levels, the 360-day year noted in that calculation, and the opposite-sign handoff after one complete Level 2 circuit. It does not turn the historical delineations into event predictions.