The number calculated is how many days that the native remained in the womb of its mother, whether the Moon be Supra or Sub terra. For example, if the Moon is Supra Terram in 3 signs and 18 degrees the length that the child remained in the womb would be for 267 days. Now in the next table, find the month and day that the child was born (make sure to note the leap or bissextile year after February). Subtract the days the child remained in the womb from the days of the birth year (if the number is too small, add 365 for the Common Year or 366 for the Bissextile Year). For example, as with the previous example, 267 days in the womb minus 120 (April 1st Common Year) equals 147. Take this remainder, look in the Table of months again and match up the Month and Day. This date will be the date of conception.
Finally, cast a second chart for the hour of noon on the day, month, and year of conception. If the native finds that the Moon is within 13 degrees of the Ascendant than the native has found the correct hour of birth. If it is still in the first House but a greater distance from the Ascendant than 13 degrees it is due to the Planetary influence which has pushed forward or retarded the birth.
Secondly, the Animodar of Ptolemy is another method which has been used in Traditional Astrology in order to pinpoint the exact time of birth. The method is as follows.
Cast a chart for the estimative time of birth. Now look to the degree of the New or Full Moon preceding the birth which happened to be above the Earth. Next look to see in the chart which Planet has the most Essential Dignities in that degree. If that Planet is found in the Medium Cœli (or M.C.) of the chart casted, match your birth chart up M.C. up to that degree where the Planet was found. If it is found that the Planet with the most dignity is found closer to the Ascendant than make the Ascendant the same degree as that Planet. If neither match, alter your time until they do and that should lead to the correct birth time.
If it happens, as Ptolemy warns, that two Planets have the same dignity in that degree then the Planet fit to be chosen is the one closest to the Ascendant and is called Lord of the Animodar. This is the method of the Animodar of Ptolemy. There is some criticism from Classical authors regarding this method and others have recommended the Trutine of Hermes to be more accurate. Since these methods are fairly simple and easy to use it is suggested to use both to verify the birth time accuracy.
The final method is of the Accidents of the Native. This is the most common method used by Modern Astrologers (albeit most of the time incorrectly) which involves asking the Native to explain the Accidents which have happened to them since their birth, all major and important accidents, specifically relating to their being/body and career. These accidents can be either good or evil and the better or worse they are, the easier it is to find their significators. If they happen to the body, then it has been because of influence by the Ascendant, if they happen with regards to career or public status, look to the M.C. This can be done by transits or even by figuring out accidents or life long deformities of caused by certain Planets inhabiting the Ascendant.
The Native may also search descriptions of the rising Signs, or certain Planets in the first House, as these give clear direction as to what the Native looks like and how they act. For example, if one finds Mars in Aries, for an individual with red hair, it is likely that Mars is in the 1st House and most likely close to the cusp. Since Aries and the 1st House both rule the head and the Planetary color rulership is a fiery red, you can be almost certain that this is the correct placement for the 1st House.
