A natal chart without a birth time

Over a day most planets hardly move: the Sun covers about one degree, Mercury, Venus and Mars less than two, the distant planets a fraction of a degree. So their signs and the connections between them are usually known even without the time.

• The Sun sign — almost always, except on days when the Sun moves into the next sign.
• The signs of Mercury, Venus, Mars and the distant planets — if they did not change sign on that day.
• Aspects between slow planets — if the angle did not cross the edge of the orb during the day.

• The Ascendant and the other angles: the Ascendant passes through all twelve signs in a day, roughly one sign every two hours.
• The houses: their boundaries are determined by time and place.
• Sometimes the Moon sign: the Moon covers about 13° a day and changes sign every two to three days. If the change fell on the day of birth, the Moon sign cannot be determined without the time.
• The Moon’s aspects, if during the day the angle managed to enter or leave the orb.

We do not guess what is missing. An unknown factor does not become either a positive or a negative conclusion in the reading: nothing is said about it at all.

People often remember the time to within an hour, or as “in the morning”. In the form you can give an approximate time and the permitted deviation — from ±15 minutes to ±2 hours. The chart is calculated for both ends of the span, and whatever matches at both ends is treated as known.

Even “around nine in the morning, give or take an hour” gives noticeably more than “I don’t know”. Where to look for the exact time is suggested by the article how to find your birth time.

The example is fictional: the positions were invented for explanation and are not calculated from anyone’s data.

A person knows only the date. On that day the Sun is in Taurus all day, Venus and Mars do not change sign either, and the Moon moves from Libra into Scorpio in the morning. So the Sun, Venus and Mars are known, the Moon is not, and there is no Ascendant or houses. If they then remember being born in the evening and give a span from 18:00 to 22:00, the Moon turns out to be in Scorpio at both ends — and becomes known.

A full reading is built even when the time is unknown: the chapters that rely on houses and angles speak only of what is known, and a chapter with no known factors at all says plainly that it draws no conclusions without the time. If you later learn the exact time for a reading you have bought, the data can be corrected: one free correction for the same person is available with no time limit.

The exact rules by which we tell the known from the unknown are described in the methodology.

If the time is not yet known, you can still build a chart — the form has the options “Approximately” and “Don’t know”. And if you would first like to find the exact time, take a look at the article how to find your birth time.