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 30–40Return to my current decade
18 Oct 2026 to 18 Oct 2036

Your cycle crossings

40markers in this window
Biorhythm milestones between ages 30 and 40Six 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 30age 31age 32age 33age 34age 35age 36age 37age 38age 39age 40 18 Oct 2026 12:00 — 30th birthday. A personal anniversary marker. 6 Dec 2026 00:00 — Physical + intellectual. Both cycles cross zero together. 26 Feb 2027 12:00 — Emotional + intellectual. Both cycles cross zero together. 27 Aug 2027 12:00 — Physical + emotional. Both cycles cross zero together. 18 Oct 2027 12:00 — 31st birthday. A personal anniversary marker. 20 Dec 2027 12:00 — Physical + intellectual. Both cycles cross zero together. 2 Jun 2028 12:00 — Emotional + intellectual. Both cycles cross zero together. 14 Jul 2028 12:00 — Physical + emotional. Both cycles cross zero together. 18 Oct 2028 12:00 — 32nd birthday. A personal anniversary marker. 3 Jan 2029 00:00 — Physical + intellectual. Both cycles cross zero together. 1 Jun 2029 12:00 — Physical + emotional. Both cycles cross zero together. 7 Sep 2029 12:00 — Emotional + intellectual. Both cycles cross zero together. 18 Oct 2029 12:00 — 33rd birthday. A personal anniversary marker. 17 Jan 2030 12:00 — Physical + intellectual. Both cycles cross zero together. 19 Apr 2030 12:00 — Physical + emotional. Both cycles cross zero together. 18 Oct 2030 12:00 — 34th birthday. A personal anniversary marker. 13 Dec 2030 12:00 — Emotional + intellectual. Both cycles cross zero together. 1 Feb 2031 00:00 — Physical + intellectual. Both cycles cross zero together. 7 Mar 2031 12:00 — Physical + emotional. Both cycles cross zero together. 18 Oct 2031 12:00 — 35th birthday. A personal anniversary marker. 23 Jan 2032 12:00 — Physical + emotional. Both cycles cross zero together. 15 Feb 2032 12:00 — Physical + intellectual. Both cycles cross zero together. 19 Mar 2032 12:00 — Emotional + intellectual. Both cycles cross zero together. 18 Oct 2032 12:00 — 36th birthday. A personal anniversary marker. 10 Dec 2032 12:00 — Physical + emotional. Both cycles cross zero together. 1 Mar 2033 00:00 — Physical + intellectual. Both cycles cross zero together. 24 Jun 2033 12:00 — Emotional + intellectual. Both cycles cross zero together. 18 Oct 2033 12:00 — 37th birthday. A personal anniversary marker. 28 Oct 2033 12:00 — Physical + emotional. Both cycles cross zero together. 15 Mar 2034 12:00 — Physical + intellectual. Both cycles cross zero together. 15 Sep 2034 12:00 — Physical + emotional. Both cycles cross zero together. 29 Sep 2034 12:00 — Emotional + intellectual. Both cycles cross zero together. 18 Oct 2034 12:00 — 38th birthday. A personal anniversary marker. 30 Mar 2035 00:00 — Physical + intellectual. Both cycles cross zero together. 3 Aug 2035 12:00 — Physical + emotional. Both cycles cross zero together. 18 Oct 2035 12:00 — 39th birthday. A personal anniversary marker. 4 Jan 2036 12:00 — Emotional + intellectual. Both cycles cross zero together. 12 Apr 2036 12:00 — Physical + intellectual. Both cycles cross zero together. 20 Jun 2036 12:00 — Physical + emotional. Both cycles cross zero together. 18 Oct 2036 12:00 — 40th birthday. A personal anniversary marker.
BirthdayTwo cyclesAll three at zeroComplete reset
Physical + intellectual6 Dec 2026age 30.1 · Both cycles cross zero together.
Emotional + intellectual26 Feb 2027age 30.4 · Both cycles cross zero together.
Physical + emotional27 Aug 2027age 30.9 · Both cycles cross zero together.
Physical + intellectual20 Dec 2027age 31.2 · 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.