The calculation of time gives a fundamental support to the calculation of the historic events. To understand the Indian history in a proper perspective, one must be aware about the ways and practice of Indian time calculation method. Infact time is the fourth dimension of the universe, which has been studied by our ancestors in a deep and expanded perspective and in a scientific manner. All of us should know about this method of calculation. This should not remain a subject in the domain of astronomers and astrologers only (fortune teller). Keeping this in mind this book is written in a manner so that a layman can understand why is it that after Monday, there is Tuesday in the calendar of the whole world? This book helps you to answer it.