Tarabala & Chandrabala (星力月力)

Your Day, Not The Day — the Personal Muhurta Matrices

Overview

A panchang tells everyone the same thing: today's tithi, today's nakshatra, today's windows. But classical muhurta practice asks a sharper question — how does today sit against YOUR birth sky? Two matrices answer it. Tarabala counts from your birth nakshatra to today's nakshatra and names one of nine taras: Sampat brings gain, Sadhana achievement, Naidhana — the destroyer — counsels stillness; the cycle repeats through all twenty-seven mansions, so every ninth star is your friend again. Chandrabala counts the transit Moon from your birth Moon sign: six of the twelve positions support you, and one — the eighth, Chandrashtama — is the classical strongest caution in all of transit astrology, the day or two each month when the tradition simply says wait. askTIAN computes both matrices from real sidereal astronomy, tells you the minute the tara changes, flags the monthly panchak window, and renders a plain verdict — with every school divergence disclosed instead of silently chosen.

Origin & history

The nine-tara scheme belongs to the core of muhurta literature — Muhūrta Cintāmaṇi and the tradition around it — and works on the 27 nakshatras in cycles of nine: Janma (your own star), Sampat (wealth), Vipat (danger), Kshema (well-being), Pratyak (obstacle), Sadhana (accomplishment), Naidhana (destruction), Mitra (friend), Parama Mitra (best friend). Count inclusively from the birth star to the day star; the remainder names the tara; three birth stars in every twenty-seven land in each — an arithmetic askTIAN proves as a theorem in its test suite. Chandrabala is the personal transit-Moon rule the panchang sites publish daily: favorable in the 1st, 3rd, 6th, 7th, 10th and 11th positions from the janma rashi, with the 8th — Chandrashtama — singled out as the position that overrides everything else. Both are personal filters laid over the universal almanac: the same day can be Amrita for one nakshatra and Naidhana for another, which is the entire point.

These matrices never left daily use — South Indian calendars print tarabala tables for all twenty-seven stars every day, and the major panchang sites compute both for logged-in users. The engineering risk in reproducing them is convention drift: which taras count as good, whether Janma is bad or merely cautionary, what exactly 'chandrabala' means. askTIAN resolved each by verification rather than choice: the tara favorability set and quality labels are locked test-for-test against the PyJHora reference implementation (good remainders {0,2,4,6,8} — Sampat, Kshema, Sadhana, Mitra, Parama Mitra); the Janma school split is disclosed on every Janma-tara response; and PyJHora's own 'chandrabalam' — which counts from candidate ascendants for electing a lagna, a different tool entirely — is named in the method string so no one mistakes the two. The panchak window ships as the tradition defines it: the Moon's run from Dhanishta's second half through Revati, which is precisely its sidereal passage through Aquarius and Pisces.

How it works

Identify yourself either directly — janma nakshatra (1–27) and janma rashi (1–12) — or by birth date and time, from which the engine computes your sidereal birth Moon on the same Lahiri ayanamsa as every Vedic system here (a defaulted birth time is disclosed in the response, because a Moon near a boundary can shift with the true hour). The engine then reads the queried day at local sunrise — the canonical panchang convention — using the shared Meeus ephemeris: the day nakshatra keys your tara with its count, name, quality and the exact minute it changes (plus what it changes to); the day Moon sign keys your chandrabala count, the favorable flag, and the Chandrashtama warning when the count is eight; and the panchak flag reports whether the Moon is inside its monthly Aquarius–Pisces run, with the Aries entry that ends it root-found to the minute. A composed verdict weighs both matrices — and defers to Chandrashtama when it appears, exactly as the tradition does. Everything is pure compute: deterministic, no LLM, with the counting arithmetic proven as theorems and the day values cross-checked against askTIAN's own verified panchanga engine.

Good for

• Personalizing any panchang display — the same day graded for YOUR birth star and Moon sign
• Chandrashtama alerts — the one-or-two days a month the tradition tells each rashi to sit out
• Tara-aware scheduling: pick Sampat and Sadhana days, avoid Naidhana, know the minute it changes
• Panchak flags for the works the tradition defers during the Moon's Aquarius–Pisces run
• Feeding all 27 stars at once to render the classical daily tarabala table
• Pairing with panchanga.compute: the universal day plus the personal filter in two calls
• Boundary-safe janma computation from a birth datetime on the shared sidereal ephemeris

Use cases

The Personal Day Banner

One call at app-open: 'Sampat tara until 14:23, Moon 10th from your rashi — a supported day.' The universal almanac becomes a personal verdict in a sentence.

The Chandrashtama Calendar

Scan a month ahead for the user's rashi and mark the Chandrashtama days — the single most-requested personal transit warning in Vedic practice, computed rather than copied.

The Daily Tarabala Table

Call once per nakshatra and render the classical 27-row table South Indian calendars print — which stars today favors, which it warns, with change times to the minute.

The Full Timing Stack

Layer over panchanga.compute and dasha.vimshottari: the day's own quality, its quality for you, and where you stand in the long cycle — the complete Vedic timing picture in three calls.

Key terms

Tarabala

Star strength: the inclusive count from birth nakshatra to day nakshatra, mod 9, naming one of nine taras. Favorable: Sampat, Kshema, Sadhana, Mitra, Parama Mitra (counts ≡ 2,4,6,8,0 mod 9).

The Nine Taras

Janma (self), Sampat (wealth), Vipat (danger), Kshema (well-being), Pratyak (obstacle), Sadhana (achievement), Naidhana (destruction — the worst), Mitra (friend), Parama Mitra (best friend).

Chandrabala

Moon strength: the transit Moon's inclusive position from the janma rashi. Favorable in the 1st, 3rd, 6th, 7th, 10th and 11th — the standard published personal rule.

Chandrashtama

The transit Moon eighth from the janma rashi — the classical strongest personal caution, recurring a day or two each month, overriding other favorable factors.

Janma Tara

The day star equals the birth star. Mainstream grading (followed here): Not Good; some regional schools soften it to cautionary — a divergence disclosed on every Janma response.

Panchak

The Moon's monthly run through Dhanishta's 2nd half–Revati (sidereal Aquarius+Pisces), during which the tradition defers specific works; ends at the Moon's Aries entry.

Janma Nakshatra / Rashi

The birth Moon's mansion and sign — the two personal anchors both matrices count from, computed here on the Lahiri ayanamsa or supplied directly.

At Sunrise

Day values are taken at local sunrise, the canonical panchang labelling convention — with the intra-day change moments root-found and reported separately.

API

The askTIAN Muhurta API computes tarabala and chandrabala from real sidereal astronomy: janma values direct or from a birth datetime on the shared Lahiri ephemeris, day values at local sunrise cross-checked against the verified panchanga engine, tara and Moon-sign change moments root-found to the minute, Chandrashtama flagged and verdict-dominating, and the monthly panchak window computed to its Aries-entry end. Conventions verified against the PyJHora reference (tara favorability set and quality labels locked as tests; its electional 'chandrabalam' variant disclosed as a different tool), the 3-stars-per-tara structure proven as a theorem, and every school divergence stated in the method string. Pure compute, no LLM, 3 TIAN.

Endpoint: POST /trpc/muhurta.personal — 3 TIAN Points. See the API documentation and Playground.