The Ephemeris – Foundation of the Horoscope post presents the standard ephemeris, which is listed for UT 00:00. UT stands for Universal Time, or the time as measured at zero longitude. (What used to be Greenwich Mean Time.) So the positions listed for any day in the ephemeris are for the planets as seen at UT 00:00, or midnight at zero longitude.
However, these are not identical to the positions as seen at a different time and place on the same day. In particular, if you look up the ephemeris at UT 00:00 for your birth date, the positions listed are not guaranteed to be identical to what will actually appear in your horoscope for your birth date, birth place, and birth time.
The Moon Position
Let’s dig deeper, using Steve Jobs’s birth data as an example. Jobs was born on February 24, 1955 at 7:15 PM in San Francisco. Here’s the standard (UT 00:00) ephemeris for February of 1955:
On the 24th of February, the ephemeris shows the Moon at 21Pi43, or at 21 degrees, 43 minutes of Pisces. But, as we will see in the following, we are looking at the wrong date for Jobs’s birthday! Why is that?
Jobs was born at 7:15 pm in San Francisco, which is in the Pacific time zone. In February, standard time was in effect, which means 8 hours behind the zero longitude of UT. So when Jobs was born, the time at zero longitude would have been 7:15 pm plus 8 hours, for 3:15 am of the next day, Feb 25! So we should really be looking at the positions listed for Feb 25.
And when we do that, we notice a dramatic change – the Moon which was in Pisces on Feb 24, has moved into the next sign, Aries, by the time Feb 25 rolled around. This is a significant development. If there is one thing we know about Jobs, he was very much an in-your-face type guy, which absolutely ties in with the Aries quality of combativeness. Jobs’s Sun is in reticent and retiring Pisces. If the Moon were in Pisces as well, he would have never returned from his spirituality hunt in Nepal!
No place or time
The upshot is that any time you feel like you want a quick insight into someone’s personality (friend, colleague, boss, potential romantic prospect, ..) to see how they might match up with yours, you can look up the ephemeris for their birth date. And you want to get as good a fix as you can on their Sun and Moon signs. But how do you know if either of these is off by a sign? Do you always need to know their birth place as well? May not be as easy to obtain, but possible to sort of ask in passing and not seem too snoopy. But asking for the birth time would definitely be seen as strange, unless you know the person really well (boss? nah!)
Suppose your boss was born on Feb 9, 1955. As chance would have it, you still have the ephemeris for Feb 1955 sitting around. So you look up the positions at UT 00:00 for Feb 9. You see that the Moon position is 13Vi31. You don’t know where or when your boss was born, but you are in luck because the Moon was in Virgo the day before as well as the day after, at UT 00:00. So chances are very high that your boss’s Moon is in Virgo. But if she was born on Feb 10 or Feb 11, you are going to have to give it a 50-50 chance of Virgo Moon or Libra Moon.
By the way, I am harping on the Moon sign for two reasons. One is that the Moon is the fastest moving of all the bodies listed in the ephemeris, so it is most sensitive to changes in place and time. The second, more important reason is that, along with the Sun, the Moon is the most important factor in the personality, and is most sensitive to changes in environment and circumstance. Leave out the Moon, and you as well give up on really knowing a person. (This is why we go often go astray if we only use the Sun sign to “guess” someone’s personality. It’s a big factor, yes, but the Moon is equally big.)
Born on a Cusp
On the other hand, the Sun sign based on birth date is not always reliable either; I’m sure you have heard of being born on the “cusp” of a sign. Cusps only happen 1 in 12 times, at the the border of each of the 12 signs. Still, you don’t want to take someone for a Scorpio when they are actually Sagittarian, or vice versa. They are vastly different signs, and you will risk offending both!
Let’s take a closer look at cusps in Ephemeris – Born on a Cusp.