Frequently asked questions

Efémeris is a web application for classical astrology built on its own astronomical engine. It calculates your birth chart, solar returns, transits, progressions, profections and zodiacal releasing following the Hellenistic tradition, and explains them in plain prose.

Efémeris uses Hellenistic, or traditional, astrology: seven planets for dignity, sect and the elemental balance, Placidus by default with whole-sign houses available, and a reading built on the planetary rulers. The outer planets are used as sensitive points and for transits, but they take no part in the system of dignities.

A newspaper horoscope talks only about the Sun sign, which is one piece among the seven planets, the twelve houses and the Ascendant. Efémeris works with the whole chart — the Ascendant, the twelve houses, the seven planets with their dignity and their sect — and gives concrete dates instead of generalities.

Access is by invitation code during this stage. You can request one from the home page, and we'll email you when access opens.

The date, time and place of birth. All three are needed: the time determines the Ascendant and with it the twelve houses, and the place determines the time zone and the coordinates.

A chart can be cast without a birth time, but the reading comes out incomplete. Without a time there is no reliable Ascendant — it changes sign roughly every two hours — and without the Ascendant there are no houses and no chart ruler, which are the backbone of a traditional reading.

The engine is our own, and its results have been checked against a professional astrologer's report on the solar return, the progressions and the annual ascendant, and against professional software on the exact moment of the solar return. It also carries automated tests that compare the Sun and the Moon against published positions.

Yes. You can save several charts and move the focus between them: when you choose one, the app switches to that person — their chart, their solar returns, their readings and the chat.

The chart is calculated by the astronomical engine, and much of the interpretation is deterministic prose written by us. The Sky Readings and the chat are written by a language model, which works only with the figures the engine has already calculated: it is never asked to compute one.

Efémeris uses Placidus by default, with whole-sign houses — the system of the Hellenistic tradition — plus Porphyry and equal houses available in the settings. Placidus and whole-sign houses differ in about half of all placements, so the choice changes the reading, and the whole app respects it.

Efémeris is not built for that. Timing techniques show which area of life comes into focus and during which periods, not which events will happen: they are there to direct your attention, not to replace a decision.

Your birth data is stored with your account so your charts can be calculated, and only you have access to it. The chart itself is not stored: positions, houses and aspects are recalculated live every time, and the only things kept are the readings you save and a summary of the year.

Yes. Each chart is deleted from the Charts section, and deleting it takes everything hanging off that person with it: their seasons, their agenda and their milestones.