The long view of three cycles

Life-Cycle Milestone Chart

Mark birthdays, paired crossings and the rare occasions when all three classic biorhythm cycles meet or fully reset.

Ages 40–50Return to my current decade
19 Oct 2036 to 19 Oct 2046

Your cycle crossings

40markers in this window
Biorhythm milestones between ages 40 and 50Six tracks mark birthdays, paired zero crossings, triple crossings and complete resets. Birthdays Physical + emotional Physical + intellectual Emotional + intellectual All three at zero Complete reset age 40age 41age 42age 43age 44age 45age 46age 47age 48age 49age 50 19 Oct 2036 12:00 — 40th birthday. A personal anniversary marker. 11 Apr 2037 12:00 — Emotional + intellectual. Both cycles cross zero together. 28 Apr 2037 00:00 — Physical + intellectual. Both cycles cross zero together. 9 May 2037 12:00 — Physical + emotional. Both cycles cross zero together. 19 Oct 2037 12:00 — 41st birthday. A personal anniversary marker. 27 Mar 2038 12:00 — Physical + emotional. Both cycles cross zero together. 12 May 2038 12:00 — Physical + intellectual. Both cycles cross zero together. 17 Jul 2038 12:00 — Emotional + intellectual. Both cycles cross zero together. 19 Oct 2038 12:00 — 42nd birthday. A personal anniversary marker. 12 Feb 2039 12:00 — Physical + emotional. Both cycles cross zero together. 27 May 2039 00:00 — Physical + intellectual. Both cycles cross zero together. 19 Oct 2039 12:00 — 43rd birthday. A personal anniversary marker. 22 Oct 2039 12:00 — Emotional + intellectual. Both cycles cross zero together. 31 Dec 2039 12:00 — Physical + emotional. Both cycles cross zero together. 9 Jun 2040 12:00 — Physical + intellectual. Both cycles cross zero together. 19 Oct 2040 12:00 — 44th birthday. A personal anniversary marker. 17 Nov 2040 12:00 — Physical + emotional. Both cycles cross zero together. 26 Jan 2041 12:00 — Emotional + intellectual. Both cycles cross zero together. 24 Jun 2041 00:00 — Physical + intellectual. Both cycles cross zero together. 5 Oct 2041 12:00 — Physical + emotional. Both cycles cross zero together. 19 Oct 2041 12:00 — 45th birthday. A personal anniversary marker. 3 May 2042 12:00 — Emotional + intellectual. Both cycles cross zero together. 8 Jul 2042 12:00 — Physical + intellectual. Both cycles cross zero together. 23 Aug 2042 12:00 — Physical + emotional. Both cycles cross zero together. 19 Oct 2042 12:00 — 46th birthday. A personal anniversary marker. 11 Jul 2043 12:00 — Physical + emotional. Both cycles cross zero together. 23 Jul 2043 00:00 — Physical + intellectual. Both cycles cross zero together. 8 Aug 2043 12:00 — Emotional + intellectual. Both cycles cross zero together. 19 Oct 2043 12:00 — 47th birthday. A personal anniversary marker. 28 May 2044 12:00 — Physical + emotional. Both cycles cross zero together. 5 Aug 2044 12:00 — Physical + intellectual. Both cycles cross zero together. 19 Oct 2044 12:00 — 48th birthday. A personal anniversary marker. 12 Nov 2044 12:00 — Emotional + intellectual. Both cycles cross zero together. 15 Apr 2045 12:00 — Physical + emotional. Both cycles cross zero together. 20 Aug 2045 00:00 — Physical + intellectual. Both cycles cross zero together. 19 Oct 2045 12:00 — 49th birthday. A personal anniversary marker. 17 Feb 2046 12:00 — Emotional + intellectual. Both cycles cross zero together. 3 Mar 2046 12:00 — Physical + emotional. Both cycles cross zero together. 3 Sep 2046 12:00 — Physical + intellectual. Both cycles cross zero together. 19 Oct 2046 12:00 — 50th birthday. A personal anniversary marker.
BirthdayTwo cyclesAll three at zeroComplete reset
Emotional + intellectual11 Apr 2037age 40.5 · Both cycles cross zero together.
Physical + intellectual28 Apr 2037age 40.5 · Both cycles cross zero together.
Physical + emotional9 May 2037age 40.6 · Both cycles cross zero together.
Physical + emotional27 Mar 2038age 41.4 · Both cycles cross zero together.
Rare whole-life markers

When all three classic cycles meet

Triple crossingAge 29.1

All three classic cycles meet at zero.

Triple crossingAge 58.2

All three classic cycles meet at zero.

Complete resetAge 58.2

All three cycles restart in their original direction.

Triple crossingAge 87.3

All three classic cycles meet at zero.

Crossing versus reset

Zero is a meeting point, not always a restart

Every classic cycle crosses zero twice per cycle: once while rising and once while falling. Two cycles can therefore share a zero crossing without restarting in the same direction.

A three-cycle zero crossing repeats after 10,626 days (about 29.1 years). A complete reset, with all three returning to zero in their original upward direction, repeats after 21,252 days (about 58.2 years).

Difference between a zero crossing and a full resetThree sine waves cross the centre line together, while arrows show that direction determines whether the moment is a full reset.shared zero crossingdirection decides reset
What the mathematics says

Why these dates repeat

Physical + emotional

Their zero crossings coincide every 322 days.

Physical + intellectual

Their zero crossings coincide every 379.5 days.

Emotional + intellectual

Their zero crossings coincide every 462 days.

These are mathematical coincidences within classic biorhythm theory, which is not scientifically established. The chart is for reflection and entertainment, not prediction.

Continue exploring

Move between a single day, a month, a whole year or the longer story of your cycles.

Daily view Biorhythm Calculator Zoom into the physical, emotional and intellectual curves around a chosen day. Month view Personal Calendar Follow the three classic cycles through a focused month-by-month calendar. Two people Compatibility Chart Place two personal patterns together and explore where their rhythms align. Seven rhythms Extended Chart Add intuition, creativity, awareness and spiritual cycles to the classic three.