The live AI commentary surface (सहज-प्रज्ञा) is currently in DEMO mode — no ANTHROPIC_API_KEY is set in this environment. Below is a structural fallback built directly from the substrate computation and the classical chapter index. The pañcāṅga itself is computed in-house (Sun within ~0.1′ (p95), Moon within ~1′ of NASA/JPL Horizons).
Tithi
द्वादशी Dvādaśī · Śuklapakṣa
Today's tithi is Dvādaśī (Bright fortnight). Classically, the tithi is the 12°-arc of lunar elongation from the Sun (E = 133.49°); thirty tithis span the synodic month, partitioned into Śuklapakṣa (waxing) and Kṛṣṇapakṣa (waning) fortnights. Mahānirvāṇa-tantra fixes each tithi's vrata-observance and its classification as a half-tithi pair for karaṇa computation. STRUCTURE ONLY — the tithi is a half-day cell of the lunar elongation, nothing more.
cite · BPHS Ch. 85 (Vrata-yoga) — vrata-cycle anchors tithi observances.
Nakṣatra
ज्येष्ठा Jyeṣṭhā (pada 2) · lord Budha · deity Indra
Today's lunar nakṣatra is Jyeṣṭhā, pada 2. The 27-nakṣatra grid is the 3³ partition of the ecliptic that anchors the Vimśottarī daśā cycle; the Moon's nakṣatra at any moment IS the seed of all nakṣatra-based timing. The presiding devatā is Indra; the daśā-lord allocated to this nakṣatra is Budha. STRUCTURE ONLY — these are taxonomic facts about the 13°20′ arc of the lunar zodiac, not statements about any individual's day.
cite · BPHS Ch. 71 (Antardaśā-phalam) — Candra's nakṣatra is the seed of the Vimśottarī mahā-daśā.
Yoga
ब्रह्म Brahma
Today's yoga (sum-of-luminaries) is Brahma. The 27 yogas are the 13°20′ partition of (λ_sūrya + λ_candra), tabulated in Sūrya Siddhānta. Each yoga has a classical śubha/aśubha classification fixed by name (e.g. Viṣkumbha, Atigaṇḍa, Vyāghāta are aśubha-classified at the limb level). This is a structural property of the limb, not a forecast.
cite · Sūrya Siddhānta · pañcāṅga-adhyāya — yoga arc computation.
Karaṇa
बव Bava
Today's karaṇa is Bava — a half-tithi cell, sixty per synodic month. Mahānirvāṇa-tantra fixes 7 movable (cara) karaṇas cycling and 4 fixed (sthira) karaṇas at the synodic boundary. The cara/sthira classification is a structural fact about the half-tithi cycle. STRUCTURE ONLY.
cite · Mahānirvāṇa-tantra · karaṇa-vidhi (cyclic 7 + fixed 4).
Vāra
शनिवार Śanivāra · Saturday
Today's vāra is Śanivāra (Saturday), whose lord-graha is Śani. Bṛhat-Saṃhitā of Varāhamihira fixes the vāra-graha order; the weekday is a cyclic-7 structure independent of the lunar cycle. The lord-graha is the classical karaka of the day-cell — a label, not a directive.
cite · Bṛhat-Saṃhitā of Varāhamihira — vāra-graha-krama.