When I work with clients, I ask for the date, time and place of birth exactly as they appear on the certificate. I don't ask for the time your mother remembers, nor the date the family celebrates, nor the city where you grew up. I ask for what was written on paper.

The reason is simple: a birth chart is a photograph of the sky at the minute you were born, seen from the place where you were born. If the minute or the place is wrong, the photograph is of another sky. And everything I say afterwards, however careful I am, will be about that other sky.

The certificate is the only record made at the time, by someone who was there or was told right away. Memory, over the years, rounds off the time, mixes up the day of birth with the day of registration and swaps the city of the birth for the family's city. Nobody does this on purpose. It is what memory does with any date.

• The date tells which sign the Sun, Mercury, Venus, Mars and the slow planets were in. They move slowly, so the date alone is enough for most of them.
• The time tells which sign was rising on the horizon: the Ascendant. From it come the Midheaven and the twelve houses, which show in which area of life each planet acts. The time also decides the sign of the Moon on the days when it changes sign.
• The place tells where the sky was seen from. Latitude and longitude change the Ascendant and the houses, and the city decides the time zone used in the calculation.

The sky makes a full turn around the Earth every 24 hours. That is why the Ascendant moves one degree every four minutes and changes sign roughly every two hours. I measured the effect of this on the houses, in São Paulo, over ten years of sky. With four minutes of error, 28% of charts already have at least one planet in another house. With fifteen minutes, 72%. With half an hour, 94%. With one hour, 99.9%.

Fifteen minutes is the difference between "I was born at ten" and "I was born at a quarter past ten". It is the size of the rounding almost every family does. The full count is in What an astrological house is.

Without the time, the chart comes out half done, and everyone knows what is missing. The signs of the planets and the aspects between them are still there, and I read that half knowing it is half.

With the wrong time, the chart comes out whole. It has an Ascendant, a Midheaven and twelve houses, and on screen it is identical to a correct chart. Nothing warns that there is a problem. I read that chart with the same care as any other, and reach firm conclusions about the career, relationships and money of someone who is not you.

It is like a GPS with the wrong starting address: the route it draws is clean, the turns make sense, and it leads to the wrong place. An astrologer who receives wrong data is led into error, and the whole analysis inherits that error.

It is the consequence that shows up most in practice. The analysis describes someone expansive, who likes the stage, and the person is reserved. It talks about a career turned towards the public, and they work alone. It says the theme of the year is the family, and their life is all about work.

Faced with this, people usually draw one of two conclusions: that astrology doesn't work, or that they themselves are wrong about who they are, and they try to fit the description. Both are bad, and neither is true. The chart was right for another time.

That is why, when a client tells me they didn't recognise themselves in a reading, the first thing I check is the birth data. Most of the time, that is where the problem is.

• The rounded time. "I was born at noon", "it was around six". The certificate usually has the minute, and the minute matters.
• The celebrated date instead of the registered date. It happens more than it seems, especially with people who were registered days or weeks after being born. Lula is a public example: his certificate says 6 October 1945, and he celebrates 27 October. I told that story in Who will win the 2026 election.
• The city of registration instead of the city of birth. Many people are born in the hospital of the neighbouring town and registered where the family lives. For the chart, what counts is where the birth happened.
• The correction made on your own. Brazil had daylight saving time in several periods between 1931 and 2019. The certificate records the clock time of that day, and the chart calculation already does the conversion. Whoever subtracts an hour before giving me the data makes the correction twice, and the chart comes out an hour wrong.

I ask for three things, copied from the certificate: the date, the time with the minutes and the city of birth. If your certificate is an old model and doesn't show the time, an updated copy, issued by any registry office, usually does.

If even then the time doesn't turn up, tell me you don't know. I would much rather read a chart without a time, knowing what is missing, than read a complete chart built on an invented time. And there is a way to get close to it, rectification, which I explain in I don't know what time I was born.

Giving the right data is the part of the work that is up to you, and it is the part that decides whether everything that comes after will speak about your life.