I mean to say that I do not think time of birth is the way to find out your correct chart.  I know this has been the tradition for thousands of years but I do not think it gave me the correct chart.  The reason is this: 
  
I am a beginner in vedic astrology, but when I first started I wore a ruby because I thought I was cancer ascendant.  I then had a dream in which I was being born and there were 3 different sections in a graph.  What I got out of the dream was that birth is not a single point of time and using time of birth to get a chart may not always be accurate. 
  
Since learning more about vedic astrology, I have had many dreams with the word Taurus in them.  And a spirit voice once told me Simha was my moon sign.  Moon sign I know is simha becuase that does not change with the hour.  Another spirit in my past told me to wear a diamond.   When I got into vedic astrology at first I did not know why that would fit since cancer ascendant is not good for diamond.   
  
However knowing I am taurus ascendant, which by the way, would be 6 hours before my actual birth time, I know diamond is good for taurus.  I have had other dreams of lapis lazuli (saturn) and emerald (venus). 
  
My chart I was reading today some examples of the stars in different houses and they fit almost perfectly if i use the time 6 hours before I was born.   I think this has to do with the beginning of labour, not time of birth.  Well your ascendant can be figured out by using times near your actual birth time.  
  
I suggest anyone whose chart does not seem right, try entering your birth time off by 1,2,3 hours etc, and see if the new chart makes more sense.