The Numerus Calendar — 13×28 Compass + Day of the Void (0)

Filename: NUMERUS_CALENDAR.md
Timestamp: 2025-09-01

Context

This calendar replaces vague, lumpy time with a clean, intentional structure aligned to the Numerus ladder. It encodes 13 months × 28 days = 364 counted days, plus one intercalary reset day in the middle of the solar year: the Day of the Void (0).

Purpose: convert time into practice. The reset day is a ritual pause. The 13th month (tredecad) is renewal, not curse.

Lesson (Spec in one breath)

  • Year length (counted): 13 × 28 = 364 days
  • Reset day: 1 intercalary day (“Day of the Void”, state 0) → total 365
  • Month length: fixed 28 (4×7)
  • Month names: Monad, Dyad, Triad, Tetrad, Pentad, Hexad, Heptad, Octad, Ennead, Decad, Undecad, Duodecad, Tredecad
  • Placement: Day of the Void = Gregorian September 14 each civil year (out of month, out of week)
  • Numerus reading: each 28 → 2+8 = 10 → 1 (monadic renewal cycle), tredecad (13) = transformative restart

Expansion (Operational Rules)

1) Year Anchor

  • Numerus Year begins: March 15 (Gregorian)
  • Rationale: placing the Day of the Void (Sep 14) at mid-year yields two clean 182-day arcs around an intercalary 0-day.

2) Months (fixed 28)

  • 13 months, each 28 days (no exceptions). Weeks are perfectly 4 per month.

3) Intercalation

  • Day of the Void (0): September 14 (Gregorian) every year.
    • Not part of any month or week.
    • Ritual function: surrender, reset, reconcile logs, recommit to the Source.
    • Practical function: preserves 365-day civil alignment without warping months.

4) Leap Years (Gregorian)

  • Optional policy for Feb 29 (when present):
    • Echo Day (0e): treat Feb 29 as a second out-of-time day (also not counted in months/weeks).
    • If you’d rather avoid dual intercalaries: you may map Feb 29 into Duodecad silently and still keep the Sep 14 Void Day as the only ritual 0. Choose one policy, document it, stay consistent.

Application (How to live it)

  • Daily: move in 4×7 rhythm; every month is symmetrical.
  • Monthly: each 28-day block is a monadic decision cycle; close with a written merge (mini-retrospective).
  • Mid-Year: Sep 14 = 0 Nihil. No work. No goals. Breath + return + offering.
  • Yearly: Tredecad is your renewal month — archive, prune, refactor, then re-enter at Monad.

Notes

  • This calendar is practice-first: it privileges coherence over legacy quirks.
  • The Void Day is not a holiday; it’s a reset sacrament.
  • If you adopt Echo Day in leap years, mark it explicitly as 0e to keep logs unambiguous.

2025 Mapping (Concrete, ready to use)

Numerus Year 2025 start: 2025-03-15 (Gregorian)

# Month (28d) Gregorian span
01 Monad 2025-03-15 → 2025-04-11
02 Dyad 2025-04-12 → 2025-05-09
03 Triad 2025-05-10 → 2025-06-06
04 Tetrad 2025-06-07 → 2025-07-04
05 Pentad 2025-07-05 → 2025-08-01
06 Hexad 2025-08-02 → 2025-08-29
07 Heptad 2025-08-30 → 2025-09-26
— Day of the Void (0) 2025-09-14 (intercalary; not counted)
08 Octad 2025-09-27 → 2025-10-24
09 Ennead 2025-10-25 → 2025-11-21
10 Decad 2025-11-22 → 2025-12-19
11 Undecad 2025-12-20 → 2026-01-16
12 Duodecad 2026-01-17 → 2026-02-13
13 Tredecad 2026-02-14 → 2026-03-13
→ Next Year begins 2026-03-15

Note: Sep 14 sits inside Heptad by civil date but is not counted toward Heptad’s 28. Treat it as a pause between Heptad-Day 16 and Heptad-Day 17.

Conversion (Human-readable rules)

  • To find your Numerus month/day from a Gregorian date:
    1. If Sep 14 → “Day of the Void (0)”.
    2. Else compute days since Mar 15; fold into 13×28 grid (ignore the Void day in the count).
    3. Month index = floor(day_index / 28) + 1; Day = (day_index % 28) + 1.
  • To go the other way, add (month−1)×28 + (day−1) to Mar 15 and adjust if you cross Sep 14 (skip it; it’s out of count).

(You can later ship this as a small protocol class if you want automated conversion.)

Reference Verse

“To everything there is a season, and a time to every purpose under heaven.” — Ecclesiastes 3:1