Western

Primary directions

The oldest predictive technique: the sky turning after your birth, converted into years of your life.

Included in the Pro plan

What is it?

Primary directions come from Hellenistic astrology and were formalised by Ptolemy. They use the sky’s daily rotation: after your birth, the Earth keeps turning and the planets seem to move towards the angles and towards other planets.

Each degree of this motion, measured in right ascension, is converted into time of life using a key (Ptolemy, Naibod…). When a planet reaches an angle or another point, you get the date of a significant period.

What it’s for

Date the great turning points of a life precisely
Complement modern techniques with the traditional method
Study classical and Hellenistic astrology
Rectify a birth time from known events

Frequently asked questions

Why are primary directions considered difficult?

Their calculation is trigonometric and depends on technical choices (time key, calculation method). Zodiac Intelligence does these calculations for you.

Do I need a very accurate birth time?

Yes: four minutes’ difference in the time shifts the dates by about a year. It is the technique most sensitive to the birth time.

How is it different from solar arc?

Solar arc moves the whole chart by the same arc as the progressed Sun. Primary directions follow the sky’s real rotation, specific to each planet.