The Moon sign is the sign the Moon was in at the moment you were born, and to find it the date alone is not enough. The Moon travels about 13 degrees a day and changes sign every two and a half days. On almost half the days of the month it changes sign at some point during the day, and on those days the time decides. That is why the calculator at the top of this page asks for three things: the date, the time and the city where you were born.

The city matters because of the clock. The Moon is at the same point of the zodiac for everyone at the same instant, but the time written on the birth certificate is local time, and the same “noon” happens at different moments in Lisbon, in São Paulo and in Copenhagen. With the city, the calculator finds the time zone of the period, summer time included, and converts your time into the exact instant at which the Moon was measured.

An example you can check. Someone born in São Paulo on 22 November 1995, at eight in the morning, has the Moon in Scorpio, at 26 degrees. Someone born the same day at eight in the evening has the Moon in Sagittarius, at 3 degrees. The Moon entered Sagittarius at 1:57 pm, on the summer time Brazil was using that year. Two people with the same birth date, on opposite sides of lunch, grew up under Moons in neighboring signs, and no table of dates would have told them apart.

The calculation uses the same ephemeris the site uses to build the birth chart, with the tropical zodiac, which divides the sky into twelve slices of 30 degrees starting from the March equinox. The Moon is the fastest body in the chart, and that is why its calculation needs the minute: half an hour of error in the time of birth moves the Moon by about 0.3 degrees, and when it is in the first or last degrees of a sign, that is enough to change the result. The calculator warns you when your case is near a change.

To the naked eye, the Moon is the body in the sky that changes the most: it grows, fills, wanes and vanishes in a cycle of about 29 and a half days between two new Moons, and it is the one that changes sign fastest. In the Hellenistic tradition it and the Sun are the two lights of the chart, and so its sign weighs almost as much as the Sun’s, in another direction. What changes every two nights, and what anyone can watch change, was given centuries ago the role of symbol for what varies inside us: mood, habit, the need for care and shelter.

The Moon can be read as what you feel before you think. One way to investigate the lunar sign is to separate what you do from what you need in order to feel at home. The Sun, in this reading, points to the direction of life; the Moon points to the ground: what soothes, what threatens, what recalls childhood without asking permission. Someone with the Moon in Cancer may recognize themselves in the need for a place to come back to, and someone with the Moon in Aquarius may recognize themselves more in the need for room to breathe among people. These are paths of investigation, and none of them counts as a verdict: a single position does not allow us to say anything about anyone.

What human question lives in the Moon? Perhaps this one: what happens in us before we decide what to feel? The distinction between what depends on us and what simply happens to us is old in philosophy, and the Moon, in the chart, sits on the side of what happens first: the reaction, the taste, the hunger for security. If that is so, knowing your lunar sign is knowing the starting point of your own reactions, and perhaps the first step toward choosing what to do with them.

There is a tension here worth investigating. If you recognize yourself in your Moon, can you notice what in you escapes it? And if you do not recognize yourself, it is worth asking whether the mismatch lies in the sign, in the time of birth or in the idea that a single point should explain everything.

The text about your Moon lives in its name, and it is the natural next step: Moon in Aries, Moon in Taurus, Moon in Gemini, Moon in Cancer, Moon in Leo, Moon in Virgo, Moon in Libra, Moon in Scorpio, Moon in Sagittarius, Moon in Capricorn, Moon in Aquarius and Moon in Pisces. Each one describes the lunar sign with the detail that a one-sentence answer cannot reach.

If you used the Sun calculator in what is my zodiac sign you already have one piece, and the rising sign calculator brings the third, and the text sign, Moon and Ascendant shows how the three talk to each other. If you do not know the time you were born, the text I do not know what time I was born tells you where to look for it.

If you want to go beyond the sign, the Basic birth chart reads the Sun, the Moon and the Ascendant together, the reading Personality and essence is devoted to building the self from these three points, and the Complete birth chart reads the whole chart, piece by piece.

The question that remains is: when something stirs you, what does your Moon ask for before any answer?

A few questions that tend to come up about the Moon sign: