Biorhythm Professional - The Biorhythm Professional helps you to calculate the biorhythmic curves for you and for anybody that you add to the profile list. You can create biorhythm matching, called compatibility view (for example with your partner, family members or friends), where it's possible to compare two person's rhythm. The application calculates 13 different biorhythmic curves.
About biorhythms, according to the wikipedia: "The theory of biorhythms claims that one's life is affected by rhythmic biological cycles, and seeks to make predictions regarding these cycles and the personal ease of carrying out tasks related to the cycles. These inherent rhythms are said to control or initiate various biological processes and are classically composed of three cyclic rhythms that are said to govern human behavior and demonstrate innate periodicity in natural physiological change: the physical, the emotional, and the intellectual (or mental) cycles. Others claim there are additional rhythms, some of which may be combinations of the three primary cycles. Some proponents think that biorhythms may be potentially related to bioelectricity and its interactions in the body."
Critical days: the days on which the primary cycle passes from positive to negative or vice versa are known as "critical" days. These days in the cycle are characterized by instability of capabilities that are related to a particular biorhythm.