Hayz Calculator — Which Planets Are in Phase in Your Chart

What the hayz means

Hayz is an Arabic word that entered the tradition through Hellenistic and Persian sources. It is usually glossed as planetary similitude, a planet being in likeness to the moment that bore it.

The rule turns on sect, the day-or-night color of a chart. Every classical planet carries a sect of its own. The Sun, Jupiter and Saturn are diurnal. The Moon, Venus and Mars are nocturnal.

A planet is in its hayz when it occupies the hemisphere that suits its sect. In a day chart, the diurnal planets want to sit above the horizon and the nocturnal ones below. In a night chart the demand reverses.

Mercury has no fixed sect. It borrows one from the luminary it follows, becoming diurnal when oriental and nocturnal when occidental. That single switch is why Mercury is the most flexible member of the table.

How we decide who is in phase

First we fix the chart's sect. A birth after sunrise and before sunset is a day chart; the rest are night charts. Your birth time and place settle this automatically.

Next we compute each classical planet's true altitude above or below the local horizon. This is a genuine geometric elevation, not a house assignment. The distinction matters, and we defend it below.

Then we compare. Same-sect planets above the horizon pass, and contrary-sect planets below the horizon also pass. Everything else is out of phase.

Two probes hold the logic honest. The night-chart Sun must read below the horizon and still count as in hayz. And every listed row must obey the same definition without a single exception.

What the report returns

For the seven classical bodies the calculator prints:

• Each planet's own sect, diurnal or nocturnal, with Mercury decided by arc.
• Its true altitude in degrees, signed above or below zero.
• Which side of the horizon it actually occupies.
• A clear in-hayz flag, plus a running count of how many of the seven are in phase.

A worked example: a night chart in London

Take London on 1 January 2000 at 17:30 UT. The Sun has long set, so this is a night chart, and the nocturnal planets now want the upper half of the sky.

The Sun itself sits at about 10 degrees Capricorn, and its computed altitude is roughly minus twelve degrees: genuinely below the horizon. Because a day-sect planet below the horizon satisfies the rule for a night chart, the Sun is in its hayz here.

Mercury, read as diurnal by its arc, is also below the horizon in this example, so it too passes. Mars, nocturnal and standing above the horizon, passes on the same logic. Three of the seven are in phase.

The Moon and Venus are below the horizon against their nocturnal call, so they miss. Jupiter and Saturn, diurnal and above the horizon, also miss. Four planets fail and three succeed. For contrast, the same city at noon in June puts the Sun high at about plus sixty-two degrees in a day chart.

How traditional readers used the hayz

A planet in its hayz was read as comfortable, able to deliver its gifts with less effort. It holds the same ground its sect prefers, so its promises come through more cleanly.

A planet out of phase was not doomed, only working against the grain of the moment. Its results arrive, but later and with more friction, all else being equal.

Hayz is a secondary dignity. It colors the judgment rather than replacing it. Rulership, exaltation and the bounds still carry more weight, and an afflicted lord stays afflicted even in its hayz.

The sect luminaries matter most. When the lord of the chart's own sect is also in its hayz, the tradition treated the whole nativity as better integrated and easier to read.

What this tool does not claim

Hayz is a hemispheric test, and we deliberately use true altitude rather than whole-sign houses. A planet can fall in the seventh house by sign and still be physically below the horizon. Reading hayz from the house ring alone would give the wrong hemisphere.

We report the seven classical bodies only, matching the sources. Uranus, Neptune and Pluto carry no sect in this doctrine and are left out of the count.

This is not a full dignity score. Hayz is one condition among many, and the calculator does not combine it into a single merit number.

Our method in one line

Positions and altitudes come from sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine), cast in Porphyry quadrant houses (whole-sign available on every chart) with a true geometric horizon for the hemisphere test. The probe pins the night-chart Sun to a below-horizon altitude that still reads as in hayz, checks that every row obeys the sect-hemisphere definition, and confirms a June-noon Sun stands high in a day chart. Every worked-example figure is reproduced by that probe. Reviewed by Dr. Amara Osei, Astronomy Reviewer.