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How NatalTruth works / How we calculate

Not sure of your birth time? Here's what your chart can show

Many people don't know their exact birth time. Here's how your chart makes the most of what you do know.

Plenty of people don't know their exact birth time, and that's completely fine. Your chart works with what you know: it shows everything your details can support, and marks the few placements that could shift within your time range.

Tell us what you know

  • Where the time comes from: a birth certificate, your own memory, a family story, or a best guess.
  • Your own words, like "early morning" or "around 2 in the afternoon".
  • An exact time, or a range such as 6:00 to 9:00.
  • How confident you feel about it.

We also take care of the details for you, such as how clocks and time zones worked in your birthplace in the year you were born.

What a time range changes

How much moves in about an hour
Ascendant (Rising sign)Moves through the whole zodiac in about a day: roughly 10 to 30 degrees an hour, often enough to change sign
House cuspsMove with the Ascendant, so a planet can change house
MoonAbout half a degree an hour, so it can change sign near a boundary
Sun and planetsMuch slower, and rarely affected
Typical figures, not results for any particular birth. The Ascendant's speed depends on latitude and season.

When you give a range, your chart is calculated across all of it. If the Moon changes sign during your possible birth window, you'll see both signs and the moment it changes.

Found your birth certificate?

Update your time whenever you like. Your earlier reports stay just as they were, so you can see what changed.

Revision history

  1. Revision 2UpdatedRewritten to read more warmly and clearly.
  2. Revision 1First published