Biorhythm Definition (Merriam Webster)
biorhythm (noun): an inherent rhythm that appears to control or initiate various biological processes - biorhythmic (adj)

Biorhythm Theory
The biorhythm theory originated in Europe during the late 1800's. This theory suggests that every person operates on three basic life cycles or 'biorhythms' that begin on the day you are born. These three biorhythm cycles are defined as physical, emotional and intellectual. Each biorhythm cycle has a high, low and critical phase. To ease interpretation, each biorhythm cycle takes the form of a sine-wave which continually repeats until the day you expire. When BioCal loads, the default calendar day and birthday are set to the current day. Note that the waveforms are aligned and begin on the same day (default birthday) and continue from that day forward.

The Physical Biorhythm Cycle
Starting at the base-line, your physical biorhythm cycle (show in red) moves up for about 6 days and then begins its downward journey. Ending the high phase on about the 12th day, it crosses the base-line and begins the low phase. Your physical biorhythm continues it's downward trend for about 6 more days, when it begins its return to the base-line. Once back at the base-line, your physical biorhythm cycle is complete in 23 days, and starts over again.

The Emotional Biorhythm Cycle
Your emotional biorhythm cycle (show in cyan) moves up for the first 7 days, then begins its downward trend toward the base-line. Returning to the base-line at the end of week 2, the 'high' phase is complete and the 'low' phase begins. Continuing down for one more week, your emotional rhythm changes course and starts it's upward 1 week trip back to the base-line. In sync with the moon, your emotional biorhythm cycle takes 28 days to complete before restarting.

The Intellectual Biorhythm Cycle
Your intellectual biorhythm cycle (show in yellow) moves up for the first 8 or 9 days. Like the other biorhythm cycles, it starts the downward trend, and returns to the base-line on day 16 1/2. Completing its 'high' phase, it swings below the base-line for another 16 1/2 days during the 'low' phase. Your intellectual biorhythm cycle is repeated every 33 days.

Secondary Pulses (Passion, Wisdom and Mastery)
Your biorhythm's secondary pulses are born by averaging two primary cycles: The passion pulse is the average of the physical and emotional cycles, the wisdom pulse combines the emotional and intellectual cycles and the Mastery pulse's parents are the intellectual and physical cycles. The two primary biorhythm cycles that influence a secondary pulse are either opposing (going in opposite directions) or synchronous (both going up or down) forces. Opposing forces create disruption in a secondary pulse.

The Critical Zone
Located between the 'high' and 'low' areas in the biorhythm graph, the critical zone is the dark gray area in the biorhythm graph where the base-line resides. When your biorhythm cycle or secondary pulse passes through this area, it is in the 'critical' phase. The duration of the critical phase for a primary cycle is usually about 2 or 3 days when transitioning from 'low' to 'high' or vice-versa. Secondary pulses can 'ride' in this area for weeks at a time. Since your body is busy adjusting to the swing in phases, the critical phase of your biorhythm is perhaps the most vulnerable time for mishaps and confusion. Be careful!

Biorhythm Interpretations
There are two major components that provide the main functionality of BioCal. One of the major components is the Gregorian Calendar (left side) that displays any month of any year between January 1583 and December 2099. The second major component is the biorhythm graph (right side) and associated birthday input fields.
When used together, the calendar and biorhythm graph can display the past, present or future condition of your biorhythms.
To interpret your biorhythms for a particular calendar day, use the buttons at the top of the calendar to change to the desired month and year you want to investigate, and then click on the day (in the calendar area). Your biorhythm for that month will be displayed on the right, with the vertical bar positioned over the day in question. You can get a text interpretation for this day by clicking on the 'Interpretations' tab.
To find a date when your biorhythms are at their best, use the buttons at the top of the calendar to scan through the months - while looking for a spot in the biorhythm graph when your rhythms are 'high'. When a month with a promising period is observed, use the slider (just below the biorhythm graph area) to move the vertical bar to the desired spot. Look at the calendar and observe the blue highlighted day. Again, you can get a text interpretation for this day by clicking on the 'Interpretations' tab.

Interpretations Page
The interpretations page is used to conclude the state of your biorhythm on a particular day. Based on the current calendar day highlighted, your interpretations can be past, present or future.

Current Date and Time
This area cannot be edited directly, as it just displays information from your operating system. If the time or date is incorrect, consult your computer user's manual regarding changing time, date and locale information.

Calendar Interaction
The lower calendar limit was defined by Julius Caesar on October 15, 1582 when he converted to our current Gregorian Calendar system. For simplification, BioCal rounds the earliest calendar date allowed to January 1583. When BioCal loads, the current month is displayed in the calendar area. A yellow or green highlight on a day in the calendar indicates the current day as reported by your operating system. When the biorhythm graph index (vertical bar) is positioned on the current day (as it is when BioCal is loaded), the yellow highlight in the calendar is blended with blue (making green) to indicate the vertical bar is positioned at the same day in the biorhythm graph. When the biorhythm graph index is moved (via the slider under the biorhythm graph), the blue highlight in the calendar 'follows' its movement. If you are not viewing the current calendar month, you will see only a blue highlight, indicating the selected position of the Biorhythm Graph index.

Biorhythm Graph Interaction
Not doing so will result in a misrepresentation of your biorhythms, or no representation at all.
A graph will NOT be displayed if the calendar month is earlier than the date of birth, or the date of birth is past the current date as reported by your operating system.
Some browsers may cause repainting anomalies.

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