Calcabala
PT

Birth Date

Birth-date reading

The numbers carried by a date, and the cycle it is passing through now.

Your birth date is read here and never leaves this page. Year, month and day.

Defaults to today. Change it to look at another year, month or day.

Sharpen the chart (optional)

The numerology above needs only the date. A birth time places the Moon precisely, and a birth city adds the houses. Nothing is sent to a server. The link in your address bar carries all of it, so anyone you send it to sees the same chart.

Start typing a city and pick it from the list — the time zone, latitude and longitude fill themselves.

How each number was calculated

Traditions differ on these formulas. Calcabala uses one method throughout and shows every step, so you can check the arithmetic against whatever tradition you follow.

  • Life Path: the month, the day and the digits of the year are each reduced on their own, then those three results are added and reduced. Reducing the parts separately is what lets a master number survive in a component instead of being lost inside one long sum.
  • Birthday: the day of the month, reduced.
  • Attitude: birth month + birth day, reduced.
  • Personal Year: birth month + birth day + the digits of the calendar year, reduced.
  • Personal Month: Personal Year + calendar month, reduced.
  • Personal Day: Personal Month + calendar day, reduced.
  • Master numbers 11 and 22 are preserved at every step, exactly as they are in a name reading. 33 is not treated as a master number anywhere in Calcabala.

Cycle numbers describe a season to reflect on, not events that will happen.

How the chart is calculated

The same tropical zodiac the synastry page draws, for one date instead of two: the Sun, Moon and eight planets at the ecliptic longitude they held, with lines joining the major aspects between them.

The numbers above and the chart below are two different traditions read from the same date. Neither derives from the other, and they are not meant to agree.

Positions come from the same ephemeris the rest of the site uses: JPL’s Keplerian elements for the planets, Meeus for the Sun and Moon, precessed to the equinox of the birth date. The measured error is a fraction of an arcminute for the Sun and Moon, a few arcminutes for most of the planets, and around ten for Jupiter and Saturn — so a sign is only ever in question within a few minutes of a cusp. Time zones, including historical daylight-saving rules, come from your browser’s own database.

Houses need an exact birth time, a recognised time zone and the birth coordinates. Without them the chart shows positions only, rather than inventing angles.

What happens to what you type

Every calculation on this site runs in your browser. There is no account and no server that receives a name or a birth date. Shared links carry reading details after the # in the address, which browsers do not transmit to a server. Calcabala counts visits with Google Analytics only if you accept it — and it is given the page address with everything after the # removed, so a shared reading never reaches Google either. Decline or change your mind from “Cookies” at the foot of any page.

City coordinates and time zones from GeoNames, used under CC BY 4.0. The list is bundled with the page: choosing a birth city never contacts a server.