Calculate your biorhythm
The biorhythm tells that your live is running in waves between highs and lows. Starting at the day of birth.
The waves have three different periods for three different aspects of your constitution:
Physical Rhythm (23 Tage)
Emotional Rhythm (28 Tage)
Intellectual Rhythm (33 Tage)
When your wave is near the zero line (horizon line) you will potentially have a bad constitution. When your line
is very high or very low, you will have a good day. There is no scientific prove of this theorie.