Why does the astrologer require reliable birth particulars?

The basic idea of needing your birth particulars is because he needs to calculate the astronomical positions for the time that you were born. How did the galaxy look like? That is what the horoscope is about. So, the astrologer uses the birth particulars so that he is able to see the configuration of the planets in the zodiac during the precise moment of birth. Astrology uses the picture of the galaxy at your moment of birth as its model to make predictions. Pyromancy diviners use the “configurations” of the melting wax of the burning candle to “see” the things that they interpret into their predictions, tea readers see how the tea leaves position themselves at the bottom of your cup to make their predictions, and astrology uses the galactic configuration of the planetary bodies for its predictions. So imagine what happens when your astrologer does not get reliable birth particulars to work with? He simply does not get to see the accurate picture of the galactic configuration during the subject’s actual birth moment, and he simply would not be able to reliably relate what he sees to your true life experiences. So what do you want to do? You want your birth particulars (especially your birth time) as correctly possible.