Compatibility by birth date: what two charts say

What two dates can and cannot say

The Sun moves about a degree a day, so a date settles its sign except around the day each month when it crosses into the next; for someone born then, the time and place of birth decide. Mercury, Venus and Mars change sign seldom enough that a date usually settles them too, and Jupiter, Saturn, the outer planets and the North Node move too slowly for one day to matter.

The Moon is another matter: at about 13° a day, nearly half a sign, a date alone seldom fixes its sign. The Ascendant, the Midheaven and the houses turn with the Earth, a full circle a day, and need the exact time and place. With dates only, each birth is taken as any moment of that day anywhere in the world; whatever could change across that span is left out rather than guessed, and a contact is kept only if it holds whatever the hour was.

Why there is no percentage

Many sites that offer compatibility by birth date print a number — 78% in love, 64% in friendship; there is none here, on purpose. A percentage is the one thing a reader could screenshot and act on, and it is exactly what the material cannot support. Any two charts carry easy contacts and difficult ones at once, and the same square that wears one pair down keeps another awake and honest.

A number would also be a judgment on somebody who never asked to be judged. What two charts can show is a pattern: where things come easily, where they catch, what each of you may need from the other. What two people do with it is written in neither chart.

Sun signs and the four elements

The Sun sign is the broadest layer — how each of you shines — and the first thing two Sun signs say is their pair of elements. Fire is initiative and enthusiasm, the urge to act first. Earth is pace and practicality, what can be touched and kept. Air is words and ideas, contact and room to think. Water is feeling and attachment, the need to be felt as well as heard.

Two signs of one element recognize each other quickly and share the same blind spots. Fire and air feed each other, as do earth and water; the other pairings ask for translation, which is not the same as distance. And the Sun is one point among many: two people whose Sun signs seem to clash can have Venus and Mars in easy conversation, and the other way round.

What a contact between two charts is

Comparing two birth charts is called synastry, and its unit is the contact: an angle between a point in one chart and a point in the other. Five angles count — conjunction (0°), sextile (60°), square (90°), trine (120°) and opposition (180°) — each within 4°, with at least one end at a point the tradition reads between people: the Sun, Moon, Mercury, Venus, Mars, Saturn, North Node, Ascendant or Midheaven. Roughly, a conjunction fuses, a trine flows, a sextile opens a door that needs a step, a square rubs and asks for work, an opposition sets two things face to face.

A contact reads differently from each side. Say your Sun stands at 14° Leo and their Saturn at 16° Scorpio: a square, two degrees from exact. From your side, their Saturn meets what you put forward with measure and caution; it may feel like a brake, or like being taken seriously at last. From their side, your Sun lands where they are careful and responsible, and they may find themselves cast as the one who counts the cost. Between friends or colleagues it is the pair where one brings the idea and the other the reality check: useful once it is said aloud, sore while it is not.

What a birth time adds

With times and places the Moon settles on its degree, and with it what each of you needs to feel at home. The Ascendant and the Midheaven join, and so do house overlays: one person’s planets in the other’s houses, showing where in your life the other person tends to land. Their Venus in your fourth house touches home and family; in your tenth, work and how you are seen.

An overlay needs the houses of the chart that receives it, which means that person’s exact time and place. If only your time is known, their planets can fall in your houses, but yours cannot fall in theirs. A missing time is not an error but a smaller chart, and the reading names what it could not see.

Two dates in numerology

In numerology each of you has a life path number: the day, the month and the year are each reduced to one digit — the master numbers 11, 22 and 33 are kept — then added and reduced again, so 14 August 1990 gives 5 + 8 + 1 = 14, and then 5. Two life paths read as two directions: a 5 beside an 8 is room and change beside structure and results, and the pair asks each to leave space for the other’s pace.

The Destiny Matrix of two dates adds each of your twelve points to the other person’s and folds every sum into one of the 22 Major Arcana: how the bond looks from outside, how feeling moves between you, what it keeps returning to. In the app, names, when you give them, add the soul urge and expression numbers, each of you is read in your own personal year, and the psychomatrix shows the cells where one of you is full and the other empty.

A reading for two without dates

When you do not know the other person’s birthday, or the question is about now rather than about two charts, the tarot reading for two needs no dates. Seven cards lie on a three-by-three table: your column, the other person’s — read only as how they may come across — and down the middle what binds you, ending in a step that is yours to take.

A dynamic, not a verdict

Whichever method you use, read the result as movement between two people, not a ruling on them. The other person’s placements and numbers are tendencies as they may come across to you, not a portrait; nothing here can tell what someone thinks, feels or intends.

This holds for every kind of bond: a square between a mother’s Saturn and her son’s Moon, or between two colleagues’ Mars, asks what a couple’s does — what happens when these two meet, and what each could do with it. And when the real question is “will they come back”, a reading here turns it into one it can answer: what do I need to understand about this bond?

The full reading in the app

In the app, the synastry reading takes both charts whole, with times and places wherever you have them: the two wheels, every contact with its orb, the house overlays in both directions, and what a missing time cost. It asks who the other person is to you, where things stand and whether to call them she, he or this person, then answers the question you bring.

Their date of birth is enough; the time and place are optional. A name you type for them stays on your page and is never sent. Their details are used only inside that one reading and deleted with it, never added to your profile or to anyone else’s. A reading for two costs one reading, like any other, and without an account it can be tried once, as your astrology try.