Oriental & Occidental Planets Calculator

Oriental and occidental describe where a planet sits in its cycle with the Sun. A planet is oriental when it rises before the Sun, appearing as a morning star to the east of it. It is occidental when it sets after the Sun, appearing as an evening star to the west. The label tells you whether the planet leads the Sun into the day or follows it down into the night, and that timing colors how the planet tends to express.

Oriental planets tend to act early and set things in motion. Occidental planets tend to respond, working with what has already taken shape. Demetra George and Chris Brennan put it plainly in Ancient Astrology in Theory and Practice: a planet rising before the Sun reads as more energized and forward, while a planet appearing after the setting Sun reads as more inclined toward rest and reflection. Same planet, different moment in its solar phase, different temperature.

Mercury and Venus are the familiar morning and evening stars, but Mars, Jupiter, and Saturn carry the same condition, and it shifts their reading just as much. This calculator runs all five non-luminaries together. For the dedicated inferior-planet reads, see the Venus morning/evening star calculator and the Mercury morning/evening star calculator.

The rule is mechanical. Compare the planet's ecliptic longitude to the Sun's. If the planet's longitude is less than the Sun's (up to the opposition point), it rose ahead of the Sun and is oriental, a morning star. If the planet's longitude is greater than the Sun's, it rose after the Sun and is occidental, an evening star. For example, with the Sun at 15° Leo and Mercury at 25° Cancer, Mercury is oriental; with Mercury at 5° Virgo, it is occidental.

The calculator does this for all five planets at once and accounts for the wraparound near 0° Aries, which is where hand calculation usually trips. The positions come from the JPL-backed Rust astro-service, so they match the of-date sky rather than an approximation.

One distinction worth keeping straight, because traditional texts assume you know it: oriental or occidental of the Sun is a statement about the planet's solar phase, the thing described above. Oriental or occidental by figure (also called by quarter or by angle) is a different, older usage that just means the planet sits in the eastern half of the chart near the Ascendant, or the western half near the Descendant. When a source says oriental without qualifying it, it means of the Sun.

Whether oriental or occidental counts as a strength depends on the planet, and here the traditions split. The medieval accidental-dignity scheme that William Lilly codified rewards the superior planets for being oriental and the inferior planets for being occidental: Saturn, Jupiter, and Mars gain dignity oriental, while Mercury and Venus gain it occidental, and the Moon when increasing in light.

The Hellenistic approach George teaches frames the same data through sect, and it sorts Mars differently. Saturn and Jupiter belong to the day team and are happiest, or rejoice, as morning stars. The Moon, Venus, and Mars belong to the night team and rejoice as evening stars. So a morning star Saturn and an evening star Venus please both systems. Mars is the one planet where the two part ways: Lilly likes Mars oriental and raw at dawn, while the sect tradition reads Mars as a night-team planet that does its better work occidental, in the evening where its heat is tempered.

The calculator leads with the sect reading and flags the Mars divergence in the result, so you can hold both. Sect rejoicing is one of the supporting conditions, alongside hemisphere and sign, that the hayz calculator and the benefic and malefic calculator also weigh.

Ancient astrology sorts the planets by gender: the Sun, Mercury, Mars, Jupiter, and Saturn are masculine, the Moon and Venus are feminine, and Mercury goes either way. Gender here names two kinds of energy, not people. Masculine energy initiates and moves faster, so its events come sooner. Feminine energy receives and moves slower, so its outcomes ripen later. Plato framed it as initiating versus receiving action; Ptolemy tied it to dryness and moisture.

Solar phase is one of the conditions that shifts a planet's gender expression. A planet becomes more masculinized when it is a morning star, rising ahead of the Sun, and more feminized when it is an evening star, following the setting Sun. So oriental nudges any planet toward the forward, initiating pole, and occidental nudges it toward the receptive, reflective pole, whatever the planet's baseline gender. An oriental Venus carries more drive than her nature alone would suggest; an occidental Mars softens from a charge into a considered move.

George adds a finer cut for those who want it: the masculinizing stretch of the cycle runs from about 15° ahead of the Sun out to roughly 120° ahead, just shy of the retrograde station, and the feminizing stretch runs from about 15° behind the Sun back to roughly 120° behind. In the modern reading these shifts are less about masculine and feminine as fixed categories and more about a planet's pace and posture, which is also why they map usefully onto a more fluid sense of gender.

Oriental and occidental are the two halves of a longer loop, the synodic cycle, and the superior and inferior planets run it differently. Mars, Jupiter, and Saturn begin each cycle conjunct the Sun, hidden in the beams. They emerge ahead of the Sun as morning stars, reach a first station and turn retrograde near the 120° trine, then oppose the Sun, rising as it sets. After opposition they trail the Sun as evening stars before sinking back toward conjunction. For these three, oriental is the rising arc from conjunction to opposition, and occidental is the descending arc back.

Mercury and Venus start at the inferior conjunction, climb to greatest elongation as morning stars (28° for Mercury, 48° for Venus), pass behind the Sun at superior conjunction, then reappear in the west as evening stars before stationing retrograde and returning. Because they never stray far from the Sun, their oriental and evening phases are tidy bookends around two conjunctions.

A planet's speed tracks this cycle, and speed tracks how actively it works. Fast and direct reads as forthright and quick to produce its results; slow or retrograde reads as delayed and internalized. The calculator flags retrograde planets and any planet within 15° of the Sun, lost in the glare. For the deeper visibility read, see the combust planets calculator and the heliacal rising calculator.

The calculator covers the five non-luminaries, but the Moon runs its own version of this cycle. It waxes from new to full as it pulls ahead of the Sun into the evening sky, then wanes from full to new as it falls back toward the morning sky before dawn. Increasing light is the building, outward half; decreasing light is the releasing, inward one.

Sources label the Moon's halves inconsistently, some calling the waxing Moon oriental and others occidental, so it reads more cleanly by its light than by the tag. A waxing Moon tends to read as gathering and growing; a waning Moon as distributing and letting go.