Please refer "The Hindu Predictive Astrology" section to guess an idea of time required to Cast any Horoscope (assuming Casting is done without considering "Ashtak Varga" and other Varga Calculations). These minimum mathematics, if done by any skilled Astrologer will take at least a few hours. But if Computerized Astrological Programmes for Horoscope Casting are utilized then any Horoscope can be casted within 1 to 2 (approx.) minutes depending on Computer System Capabilities. Thus readymade computerized Software(s) can help us for Casting any Horoscope very Quickly. However if provided Birth Details are faulty then mere faster calculation by even super fast computer yields fruitless result.