Your Sun, your Moon and your Rising sign
Your star sign is only one of the three pieces. The Moon says how you feel behind closed doors, and the rising sign says how people see you when they meet you. Put in your date, time and city of birth and you get all three.
If your town is not on the list, pick the nearest large city: a few kilometres will not move the result. One hour of error changes the rising sign nearly half the time, so the birth certificate is worth a look.
The calculations are real astronomy — the actual position of the Sun, the Moon and the horizon at that instant, with whatever summer time applied that day in that place. The interpretations are astrological tradition: take them as a way of looking at yourself, not as a diagnosis.
When somebody asks «what's your star sign?», they are asking about one of three pieces. The Sun sign says a lot, but it arrives late to two important questions: what you are like once your front door is shut, and what impression you make when somebody meets you. That is what the Moon and the rising sign are about.
The Sun is your core: where you pull when nobody is making you. The Moon goes inward — it changes sign every two and a half days, so hardly anyone knows theirs, and it explains what you need in order to feel settled. The rising sign is the sign that was climbing over the eastern horizon at the exact moment you were born: the first impression you make, the way you walk into rooms and start things.
And that is why the time is asked for: the rising sign changes roughly every two hours. No figure in astrology depends so much on the clock. We measured it across five hundred births: a single hour of error moves the rising sign fifteen degrees on average and changes the sign for half of people. The birth certificate is worth more than memory here.
There is one more trap, and most online calculators do not deal with it: the summer time in force that day. Britain spent 1968 to 1971 on British Standard Time — one hour ahead of Greenwich all year round, with no clock changes at all — and the United States moved its daylight saving dates several times. Anyone born in January 1970 in London therefore has an hour that the «it's winter, so GMT» calculators get wrong. Nothing is assumed here: you pick the city and the calculation asks the time zone database, with every historical rule, year by year.
And if you do not know the time? Tick the box and you get the Sun and the Moon, worked out for noon. If the Moon changed sign that day, the app tells you that this one is uncertain without the time — which is more honest than handing you a sign and saying nothing.
The calculations are astronomy: the real position of the Sun, the Moon and the horizon at that instant. The interpretations are something else — astrological tradition, for looking at yourself with curiosity, not for diagnosing yourself. To keep pulling the thread: the daily horoscope, zodiac sign compatibility and the moon calendar, which runs on the same engine as the Moon on this page.