The charts display a period of 3 days before and 14 days after the target date. Positive periods of the cycle indicate high ability days and its negative periods show low ability days. Near zero means critical days. It is said that human body has three rhythms with a fixed cycle:
1. Physical biorhythm (23-day cycles) is related to physical strength, durability, resistance, stamina, courage and etc.
2. Emotional biorhythm (28-day cycles) is related to emotional stability, feeling, intuition, mood, susceptibility, creativity and etc.
3. Intellectual biorhythm (33-day cycles) is related to thinking, analyzing, judgment, concentration, composition and etc.