Moon sign calculator: what your heart needs

Your Moon sign is the zodiac sign the Moon was in at the moment you were born. In astrology it stands for your emotional world: what you need to feel safe, how you react on the spot and what calms you down when the day was too much.

Where the Sun shows what you want to be, the Moon shows what you need. Many people notice it in small things: after an argument one person needs to talk it through right away, another needs a walk alone first. Differences like these are what the Moon sign describes.

The Moon circles the Earth in a little over 27 days and passes through all twelve signs on the way. So it stays in one sign for only two to two and a half days, moving on by about half a degree every hour. That is why people born in the same week often have different Moon signs.

On a day when the Moon changes sign, the time can decide. So we check the margin of your birth time: if the Moon changes sign inside it, we show you both signs and the time of the change.

If you do not know your time, we calculate the Moon for noon on your birthday and check the whole day, from midnight to midnight. If the Moon stays in one sign all day, your Moon sign is certain even without a time. That is true on a little more than half of all days.

If the Moon changes sign on your birthday, we show you both signs and the time of the change. Then your birth time decides. We do not calculate a rising sign without a time, because it changes about every two hours.

The Moon rarely tells the whole story. An Aries Sun with a Cancer Moon can come across as quick and bold and still need a lot of comfort and closeness. That is why the calculator reveals your big three: Sun, Moon and rising sign.

From the date, time and place we first work out the exact moment of your birth in universal time, using the time zone and daylight saving time that applied at your birthplace back then. If your time falls in an hour that happened twice because the clocks went back, we ask instead of guessing. For that moment, the Swiss Ephemeris, a library of planetary positions widely used in astrology, gives the position of the Moon in the tropical zodiac of Western astrology. We do not store your details.