Rhythm & Bio uses mathematical calculations in an attempt to predict a person's performance in several areas according to biological rhythms. This program shows those calculations in the form of graphic curves on a chart. The curves are color coded and, thus, you can easily see how your different energy levels will be on a given day. The program shows three different energy curves: physical, emotional and intellectual. To obtain your personal data, you only need to enter your birth date (month, day and year) and, optionally, your name(s) and surname. By clicking on the Bio Rhythms Computation button, the program will calculate your biorhytms for a one-month period. Interestingly, the program also gives you the critical days you will have for a six-month period, as well as the double- and triple-critical days for a six-month and for a six- and thirty-year period, respectively. If you are planning to engage in a relationship, then you may want to check your biorhythm compatibility with your beloved one. The program allows you to do so by entering the birth date of the other person and clicking on the Compatibility button. Although biorhythm is not considered as an exact science, this program may be useful for you to plan your daily activities.