Panchangam Reference

Sunrise-anchored Ghati clock ​

derived.ghati-clock

The interval from sunrise to next sunrise is divided into 60 proportional Ghatis.

Assurance ​

LevelCurrent statement
Documented and traceableYes — the canonical record includes the process and a worked example.
Regression or reproduction checkedLinked to 1 repository test file(s).
Independently source-supportedPartial support only; read the provenance note and limitations before generalizing.

Computation method ​

Method type: formula

Normalize the local sunrise-to-next-sunrise interval to 60 equal Ghatis and convert linearly in either direction.

Process ​

  1. Subtract sunrise from next sunrise in seconds.
  2. Divide by 60 to obtain seconds per Ghati.
  3. For civil-to-Ghati, divide elapsed seconds since sunrise by that scale.
  4. For Ghati-to-civil, add the scaled Ghati duration to sunrise.

Formulae ​

Ghati scale ​

text
s_g = (T_next_rise - T_rise) / 60; g = (t - T_rise) / s_g; t = T_rise + g*s_g
  • s_g: seconds per proportional Ghati
  • g: Ghatis since sunrise
  • t: civil instant

Worked example ​

Twenty-four-hour sunrise day ​

Inputs

  • Sunrise: 06:00
  • Next sunrise: 06:00 next day
  • Civil instant: 12:00

Calculation

  1. 86,400 / 60 = 1,440 seconds per Ghati.
  2. Six elapsed hours / 24 minutes = 15 Ghatis.

Result

  • 12:00 corresponds to Ghati 15.0

Method notes ​

  • The scale intentionally follows the observed local Panchangam day; it is not hard-coded to 24 civil minutes.

Contract ​

Owning layer: derived
Claim kind: deterministic-fact
Time basis: Local sunrise to next local sunrise, divided into 60 equal parts.

Inputs ​

  • sunrise
  • next sunrise
  • civil instant or Ghati value

Outputs ​

  • seconds per Ghati
  • civil/Ghati conversion
  • Ghati window

References and evidence ​

Evidence classes: textual
Verification states: partially_verified

Conversion behavior is tested; the textual use of scaled Ghatis is covered only in part.

panchangam.mixed_daily_windows ​

Evidence class: textual
Verification state: partially_verified
Locator: B. V. Raman, Chapter III, Nakshatra Tyajyakala table, inspected in the 2020 Chistabo derivative at internal printed p. 7 (physical PDF p. 10), and Chapter V section 7, Durmuhurta, internal printed p. 13 (physical PDF p. 16); regional tables remain regression-pinned
Last reviewed: 2026-09-04
Scope: The auspicious, inauspicious and Choghadiya response objects are mixed containers. Raman supports the four-Ghati Nakshatra Tyajyakala concept and his printed Durmuhurta scheme, but the project's regional weekday tables are not identical to Raman's table and the remaining Brahma Muhurta, Abhijit, Amrita Kalam, Rahu Kalam, Gulika, Yamagandam and Choghadiya components do not yet have criterion-level textual claims. This state records partial evidence, not umbrella verification.

Sources ​

The complete machine-readable source registry is available in provenance.json. A regression fixture or same-code reproduction is not independent verification.

Reproduce and review ​

Run the linked tests, then the complete offline contract:

bash
python tools/verify_project.py

Public surfaces ​

  • python-library
  • mcp
  • website

Limitations ​

  • A Ghati is proportional to that local sunrise-to-sunrise interval, not fixed to civil minutes.

Implementation ​

This route is generated from computations.json. Edit the registry and canonical reference prose in the same pull request as a behavior change.