Three cycles of 23, 28 and 33 days, counted from the day you were born. It is arithmetic on a day count, and the page draws the curves so you can see exactly that.
Example22 November 1988pick your own date
Point at a day to see all three values. The dotted line is today.
Above the centre line is the high half of a cycle. Below it is the low half. The crossings are dated underneath.
Day 13,776 of your life, as at 11 August 2026.
| Cycle | Length | Next crossings |
|---|---|---|
| Physical | 23 days | 12 Aug 2026, 24 Aug 2026, 4 Sep 2026 |
| Emotional | 28 days | 11 Aug 2026, 25 Aug 2026, 8 Sep 2026 |
| Intellectual | 33 days | 13 Aug 2026, 29 Aug 2026, 15 Sep 2026 |
| Cycle | Length | What it tracks |
|---|---|---|
| Physical | 23 days | Strength, coordination, endurance, stamina |
| Emotional | 28 days | Mood, creativity, sensitivity, intuition |
| Intellectual | 33 days | Analytical thinking, memory, alertness |
Physical is 23 days, emotional is 28 and intellectual is 33. All three start together on the day you were born and never quite line up again. All three coincide again only after 21,252 days, which is a little over 58 years.
A cycle at its peak or trough is said to matter less than the day it crosses zero, when it is changing sign. Those dates are listed above. They are arithmetic on a day count, and nothing is measured.
Biorhythm was invented in the late nineteenth century by a Berlin physician and has no connection to the sky, to Jyotish, or to your chart. It is on this site because people look for it, and it is kept apart from the pages that read a birth chart.
Physical Cycle (23 days): Affects strength, endurance, coordination, and overall physical well-being. Emotional Cycle (28 days): Influences mood, creativity, sensitivity, and emotional stability. Intellectual Cycle (33 days): Governs analytical thinking, memory, alertness, and logical reasoning. When a cycle is positive, that area is enhanced.
Critical days occur when a cycle crosses the zero line — transitioning from positive to negative or vice versa. These are considered times of instability and lower performance in that area. When two or three cycles are critical simultaneously, extra caution is advised. Understanding your biorhythm helps plan important activities during peak periods.
Biorhythm theory proposes that human performance follows three fixed cycles starting from birth: Physical (23 days), Emotional (28 days), and Intellectual (33 days). Each cycle follows a sine wave pattern oscillating between positive and negative phases. The theory was developed in the late 19th century by Wilhelm Fliess.
Your sun sign comes from the day. Your lagna moves a whole sign every two hours — free, and no sign-up.