Firdaria
What are Firdaria (Planetary Periods)
Firdaria is an ancient Persian system of predictive astrology that divides a person’s life into major periods, each ruled by a specific planet. It is believed that the ruler of the current firdar sets the main backdrop of life, the key themes and value system of a person for that period.
The total cycle of firdaria is 75 years (the sum of the years of rulership of all planets and the lunar nodes). If a person lives more than 75 years, the cycle begins again.
Each major period (firdar) is additionally divided into 7 equal sub-periods (sub-firdaria), each of which is also ruled by its own planet. The first sub-firdar is always ruled by the same planet as the main period, and then they change in accordance with the Chaldean order.
Diurnal and nocturnal birth The order of succession of the major periods depends on whether the native has a diurnal or nocturnal chart (whether the Sun is above or below the horizon):
- For a diurnal birth, the cycle begins with the Sun, and then the periods change in Chaldean order: Sun (10 years) → Venus (8 years) → Mercury (13 years) → Moon (9 years) → Saturn (11 years) → Jupiter (12 years) → Mars (7 years).
- For a nocturnal birth, the cycle begins with the Moon: Moon (9) → Saturn (11) → Jupiter (12) → Mars (7) → Sun (10) → Venus (8) → Mercury (13).
After 70 years of rulership by the main seven planets, short periods of the North Node (3 years) and South Node (2 years) follow.
Calculation variants: Al-Biruni and Bonatti
Two approaches to the calculation of firdaria for nocturnal birth have historically developed in the astrological tradition. The disagreements concern exclusively the position of the Lunar Nodes in the nocturnal chart.
Calculation variants: Al-Biruni and Bonatti
Two approaches to the calculation of firdaria for nocturnal birth have historically developed in the astrological tradition. The disagreements concern exclusively the position of the Lunar Nodes in the nocturnal chart.
1. Al-Biruni’s method (Traditional / Robert Hand) The 11th-century Arab scholar Al-Biruni described a system in which the Lunar Nodes always conclude the 75-year cycle, regardless of the time of birth.
- Diurnal chart: Sun … Mars → North Node → South Node.
- Nocturnal chart: Moon … Mercury → North Node → South Node. This variant is used by default in most modern astrological programs.
2. Guido Bonatti’s method (Robert Zoller) The 13th-century Italian astrologer Guido Bonatti broke this symmetry. In his system, for nocturnal birth the Nodes are placed not at the end of life, but at the end of the first half of the cycle (after Mars, preserving their astronomical position relative to the Sun).
- Diurnal chart: Sun … Mars → North Node → South Node (same as Biruni).
- Nocturnal chart: Moon → Saturn → Jupiter → Mars → North Node → South Node → Sun → Venus → Mercury.
Note: For people born during the day, both methods produce absolutely identical results at any stage of life. The difference appears only for nocturnal birth charts. The choice of method depends on the personal experience and preferences of the astrologer.
Implementation in the Zeus program
Firdaria can be calculated using two algorithms: Al-Biruni and Bonatti.
The Periods control allows you to extend the calculation time interval by cyclically repeating the full Firdaria cycle.
By clicking on a sub-firdar row, the corresponding sub-sub-firdar can be seen in the right table.
Context menu
The start of the selected period can be applied to any of the dials using the context menu.