Quite often you’ll hear an astrologer mention that ‘if you don’t know your exact birth time and your exact birth location, your chart will not be accurate.’ Thus, there is this feeling that you’ve got to know your birth time right down to the second and the birth location right down to the building.
Well, if you look at this issue relative to how the earth spins, you’ll start to realize that there is extra room in the interpretation which allows a person to be ‘close enough’ regarding the location and time.
I cover what I state below in this video:
This issue is this: how accurate must my birth location be in order to get an accurate report?
The example is, can you use the city in which you were born if you were born 5 miles outside the town?
Well, the time written on your birth certificate is usually accurate to the minute. Yet, if there is any complication during delivery that delays the doctor from calling the exact minute of birth, what is written might be a few minutes off. Thus, is it accurate enough and how does that relate to the location on the earth?
To get a feel for this, you’ll have to figure out what a reasonable accuracy ‘zone’ is for astrology.
When I think about this, the important point that determines your astrology house layout is the rising sign – the degree & minute. It would be important to figure out how many miles on the earth’s surface would fall into the time frame to figure out the accuracy of a minute.
This involves a little math. Searching on Google, we find that the circumference of the earth measured at the equator is about 25k miles. If you travel 45 degrees north or south, you’ll find that the circumference at that point is about 17,500 miles. Because this northern point covers northern US and pretty much the center of Europe, we’ll use that circumference.
Time wise, a day is 24 hours of 60 minutes each giving us 1,440 minutes in a day. Because the earth spins east to west, we can divide the circumference into the distance traveled per minute which is just about 12 miles per minute (17 miles per minute at the equator).
This basically means that during a minute, the perfect tangent line that represents the rising sign spans 12 miles in each minute.
If the person that delivered you was perfect in their timing, all the people born in that 12-mile zone (east to west) would have the same minute on their birth certificate. If the doctor was off by a minute or so (either way) the latitude area covered by the clock could easily stretch another 12 miles east or west.
Thus, having a situation where you’re birth certificate lists a location that is 5 miles from your actual birth location is probably accurate enough to get the same (or very nearly identical) rising sign degree and minute.
If you have a birth certificate that lists a time value that is a quarter hour increment, it is probably a reasonable assumption that they guessed at the time you were born. On these birth certificates, the margin of error for the location is larger. Thus, the ‘zone’ for the latitude location is larger, maybe 5 minutes either way, which makes for a 60-70-80 mile range for calculating your rising sign.
So, when using your birth location to calculate your rising sign, you want to be within a reasonable distance from your actual birth location. It’s not uncommon for this distance to be 10 miles (east or west). This would still be considered very accurate.
The only complication is when your rising degree is nearly perfectly on the cusp of a sign – ether nearly perfectly 0 or 30. Anyone that has a chart where the rising sign falls in this zone should investigate their situation in order to determine for themselves if the doctor stated the correct time on the birth certificate by inspecting the traits of each sign to see how they are reflected in your own personality. You have to determine the adjustment that needs to be made to your chart.
In my experience, when choosing the location to generate the latitude points for a report, any location within about 10-15 miles works just fine.