There are tide like changes going on within you even as you read these words. Today science knows that there are permanent cycles of physical, intellectual, and emotional energies at work within all of us. Theses cycles begin with our birth, and can be charted on a calendar so that we know what our performance potential is at any given date, as well as the ricks we run on critical "down" days. This book clearly explains these inner rhythms and how they affect every facet of life. Even more important, it shows you how to easily and exactly calculate your own personal biorhythm patterns and use them as invaluable allies rather than hidden enemies. "Know Yourself" has long been the first commandment of human wisdom. Now you can know yourself in a new, fascinating and vital way.