Planetary rashi ingresses

calendar.rashi-ingresses

Sidereal sign changes, including retrograde re-entry, are found over a requested range.

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	Not independently verified at this level; current behavior is regression-pinned.

Computation method

Method type: algorithm

Follow sidereal longitude through adaptive time steps, bisect each 30-degree sign-index change, and continue past the crossing so direct and retrograde re-entries are both emitted.

Process

1. Validate the planet subset and select the requested ayanamsa.
2. Compute sidereal longitude and speed; add 180 degrees for Ketu because it shares Rahu's Swiss body.
3. Choose an adaptive step from distance to the nearest sign boundary and absolute speed.
4. When the sign index changes, bisect for 44 iterations and record the new Rashi.
5. Search again just after entry for its exit, repeat through the inclusive range, sort chronologically, and restore Lahiri mode.

Formulae

Rashi index

r = floor((lambda mod 360) / 30) mod 12

• lambda: configured sidereal longitude
• r: zero-based Rashi index

Worked example

Sun enters Makara, 2026

Inputs

• Range: 2026-01-01 through 2026-02-28
• Planet: Sun
• Ayanamsa: Lahiri

Calculation

1. The sign index changes to Makara and the crossing is bisected.
2. The following crossing supplies the exit from Makara.

Result

• Makara entry: 2026-01-14 09:37:19 UTC
• Makara exit/Kumbha entry: 2026-02-12 22:38:58 UTC

Method notes

• The Moon is intentionally absent from INGRESS_PLANETS; the output does include retrograde re-entry rather than assuming sign order is always forward.

Contract

Owning layer: calendar
Claim kind: deterministic-fact
Time basis: UTC Julian-day crossing search.

Inputs

• date range
• planet
• sidereal longitude model

Outputs

• ingress instant
• from rashi
• to rashi
• motion direction

References and evidence

Evidence classes: astronomical
Verification states: engine_pinned

Crossing behavior is regression-tested; independent event-cell evidence is not registered.

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_ingress.py

Run the linked tests, then the complete offline contract:

python tools/verify_project.py

Public surfaces

• python-library
• mcp

Limitations

• Moon is excluded and results follow the fixed sidereal model used by this module.

Implementation

• owner: telugu_panchangam/ingress.py — rashi_ingresses

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