Short description of Biorhythms Guide 2.7.1: Biorhythms Guide is a dialog-based application, which calculates (using Kotelnic's method) the dates of the so called "days of tiredness". It allows you to predict such days and prevent or at least minimize undesirable consequences. The software features a simple, user-friendly interface, and short, yet detailed, help, which includes the overview of the biorhythms fundamental basis.