How to Find a Birth Date from a Birth Chart

How to Find a Birth Date from Astro Positions

Can you find a birth date given astrological placements alone?

The answer is “yes” but it can be “no” depending on which astrological placements are known.

For example, you can’t determine a birth date given something as simple as “Sun is in Gemini and Moon is in Cancer” since this combination occurs several days every year. But if we’re given Gemini Sun, Cancer Moon, and Saturn in Capricorn, we can narrow things down to fewer dates. Add Pluto in Scorpio, and we can narrow things down even further.

It’s best to understand how to use an ephemeris for this task. However, a charting program can work, with some trial and error, as long as you know the general times when the outer planets (Jupiter, Saturn, Uranus, Neptune, and Pluto) were in particular signs.

You’ll begin with the outermost planet that you know and work your way back.

It will be easiest if you have all the main positions. For example, if you have the following:

Given the above, we first look at Pluto, which is in Scorpio at 6 degrees and 39 minutes. Because Pluto moves through the signs so slowly–its cycle is many years–and we know the person was born in the last century, it’s easy to narrow things down to a year or two. We also note that Pluto is retrograde (it often is) which gives us further information since this can narrow things down to a birth year.

If we have an ephemeris (which is invaluable for anyone studying astrology), flipping through it will eventually lead to the year in question. However, if you don’t have one, you can also research when Pluto transited Scorpio. After googling “Pluto in Scorpio dates” I see that at least one site is saying this happened between November 1983 and November 1995. Since there are 30 degrees in a sign and Pluto is at 6 degrees, it’s earlier in the period than later. At this point we can enter a random date in a chart calculator, judge it to be about 1986 (1983 + one-fifth of the 12 years) and then enter June 1, 1986 and check out the other planetary positions to see how close we are. Knowing the Sun sign is Aries makes March/April more logical to use.

Or we can take a look at the ephemeris for 1986, and see if we’re at about 6 degrees Scorpio. If Pluto is around there, we might look at the Sun at 11 degrees Aries, which allows us to narrow things down to a date when the Sun is in Aries, from approximately March 21 to April 21 give or take.

The correct answer is April 1, 1986.

Explore further: Determining a Date of Birth From Astrology Data.