Many a sciences have attempted to predict the life span of a human being, but have conceded that an accurate assessment of life span is not only a difficult proposition, but also arguably, is impossible. This has been a dark area in the field of astrology as well. Is human life subject to the whims of Shiva, or is there a measurable method to His will? Everyday, we come across cases that are baffling, like the case of twins where the basic birth chart does not change much except by a few degrees of ascendant, but one twin only lives for a short period, while the second lives on to a ripe old age. How can one foresee this? The book provides a simple astrological method to assess the life span of human life and predict the longevity block of a subject in terms of ? short, medium or a full life. This is equally applicable to the charts of twins. The timing of demise is then calculated by using the Nirayana Shoola Dasha.