Firdaria (Planetary Periods) #

FirdariaFactory computes the firdaria, a Persian time-lord technique that divides life into a fixed sequence of planetary periods. The sequence depends on the chart’s sect: diurnal charts begin with the Sun (10 years), nocturnal charts begin with the Moon (9 years). The full 75-year cycle runs through the seven classical planets and the two lunar nodes.

Each major period (except the nodes) is subdivided into seven sub-periods, one per classical planet, beginning from the major lord itself and cycling through the Chaldean order.

All date arithmetic runs on Julian Days over the subject’s local wall-clock anchor, so deep-BCE births are fully supported. A firdaria “year” is the Julian year of 365.25 days.

Basic Usage #

from kerykeion import AstrologicalSubjectFactory, FirdariaFactory

subject = AstrologicalSubjectFactory.from_birth_data(
    "Jane", 1990, 6, 15, 12, 0,
    lng=12.4964, lat=41.9028, tz_str="Europe/Rome", online=False
)

firdaria = FirdariaFactory.from_subject(subject, target_date="2026-06-04")
print(f"Sect: {'Day' if firdaria.is_diurnal else 'Night'}")
if firdaria.current:
    print(f"Current lord: {firdaria.current.lord} ({firdaria.current.years} years)")
if firdaria.current_sub:
    print(f"Current sub-lord: {firdaria.current_sub.lord}")

Methods #

`from_subject(subject, *, target_date=None, life_cap_years=120)` #

Build the firdaria timeline for a subject.

Parameter	Type	Default	Description
`subject`	`AstrologicalSubjectModel`	–	The natal chart. Requires a real sect (`is_diurnal` must be a boolean). Midpoint composites are rejected.
`target_date`	str (ISO date/datetime) or None	None	Date the current period is resolved against. Astronomical year numbering accepted. When omitted, now in the subject’s timezone.
`life_cap_years`	int	120	How far the timeline extends, in years of life. Values below 1 are raised to 1. Periods are emitted whole, so the last one can end past the cap.

Returns: FirdariaModel

Raises: KerykeionException when the sect is unresolvable, the birth moment is missing, or target_date is unparseable.

Data Models #

`FirdariaModel` #

Field	Type	Description
`is_diurnal`	`bool`	Sect the sequence was chosen from.
`periods`	`list[FirdariaPeriodModel]`	Major periods from birth, in order. The sequence is unrolled until the life cap is reached, and the period that reaches it is kept whole: with the default cap of 120 a diurnal timeline ends at age 126.
`current`	`FirdariaPeriodModel \| None`	The major period containing the target date, if any.
`current_sub`	`FirdariaSubPeriodModel \| None`	The sub-period containing the target date, if any.

`FirdariaPeriodModel` #

Field	Type	Description
`lord`	`str`	Ruler of the period (classical planet or `North_Node` / `South_Node`).
`years`	`int`	Length of the period in firdaria years.
`age_start`	`int`	Age at which the period begins.
`age_end`	`int`	Age at which the period ends.
`start`	`str`	Local ISO datetime (`YYYY-MM-DDTHH:MM:SS`) the period begins.
`end`	`str`	Local ISO datetime the period ends.
`sub_periods`	`list[FirdariaSubPeriodModel]`	Seven sub-lord periods (empty for the nodes, which are not subdivided).

`FirdariaSubPeriodModel` #

Field	Type	Description
`lord`	`ClassicalPlanet`	Planet ruling the sub-period.
`start`	`str`	Local ISO datetime the sub-period begins.
`end`	`str`	Local ISO datetime the sub-period ends.

Period Sequences #

Sect	Sequence (lord, years)
Diurnal	Sun 10 → Venus 8 → Mercury 13 → Moon 9 → Saturn 11 → Jupiter 12 → Mars 7 → NN 3 → SN 2
Nocturnal	Moon 9 → Saturn 11 → Jupiter 12 → Mars 7 → Sun 10 → Venus 8 → Mercury 13 → NN 3 → SN 2