Thirty named Muhurtas

derived.named-muhurtas

Day and night are each divided into fifteen named proportional Muhurtas.

Assurance

Level	Current statement
Documented and traceable	Yes — the canonical record includes the process and a worked example.
Regression or reproduction checked	Linked to 1 repository test file(s).
Independently source-supported	Available only for the explicitly named provenance claims or comparison cells.

Computation method

Method type: formula

Tile daylight into fifteen equal named windows and, when next sunrise is available, tile the night into fifteen more.

Process

1. Compute daylight duration and divide it by 15.
2. Emit DAY_MUHURTAS in order with exact adjacent boundaries.
3. If next-day data exists, divide sunset-to-next-sunrise by 15 and emit NIGHT_MUHURTAS.
4. Mark daytime index 8 as Abhijit only when the engine exposes Abhijit; mark night index 14 as Brahma.

Formulae

Named Muhurta boundaries

day_i = [rise + (i-1)D/15, rise + iD/15]; night_i = [set + (i-1)N/15, set + iN/15]

• D: sunset minus sunrise
• N: next sunrise minus sunset
• i: one-based index from 1 through 15

Worked example

Hyderabad, 2026-06-11, Drik Ganita

Inputs

• Sunrise: 05:41:11 IST
• Sunset: 18:50:12 IST
• Next sunrise: 05:41:17 IST

Calculation

1. Daylight / 15 = 52m36s approximately.
2. Night / 15 = 43m24s approximately.

Result

• Day index 8, Vidhi/Abhijit: 11:49:23-12:41:59 IST
• Night index 14, Brahma: 04:14:28-04:57:52 IST

Method notes

• Wednesday keeps the eighth named daytime interval but does not label it as Abhijit because the engine suppresses that window.

Contract

Owning layer: derived
Claim kind: textual-rule
Time basis: Fifteen equal day parts and fifteen equal night parts.

Inputs

• sunrise
• sunset
• next sunrise

Outputs

• 30 named day/night windows and dispositions

References and evidence

Evidence classes: textual
Verification states: verified

The checked table is maintained in docs/reference/07-muhurta-table.md and parity-tested.

No registered claim ID; the provenance note below is the current disclosure.

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

• tests/test_named_muhurtas.py

Run the linked tests, then the complete offline contract:

python tools/verify_project.py

Public surfaces

• python-library
• website

Limitations

• Names and dispositions follow the project's verified table; other almanacs may label variants differently.

Implementation

• owner: telugu_panchangam/muhurtas.py — named_muhurtas
• mirror: src/data/muhurtas.ts — MUHURTA_DAY

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