There are tons of sites on astrology and palm-reading.  Just google it.

A friend of mine was an expert on reading charts.  She had a software that printed out the kundali (this one was circular, whereas our bahuns draw rectangular ones) based on time, date and place of birth.  But she too could not convincingly explain to me why time, date and place of birth is so important. 

If the planets set your future the moment you come out of birth canal, why could they not have any effect while you are in the womb for 9 months preceding that event?

I am still searching for answer.