{"id":"vidhyamitra:day:2021-10-13:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/2021-10-13","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"2021-10-13","date_display":"October 13, 2021 CE","panchanga":{"method":"Sūrya Siddhānta + Bhāskara-II iterative manda + Kerala-school (Mādhava-Nīlakaṇṭha) evection + variation + annual equation","engine_version":"2.0 (Kerala-school enhanced)","accuracy_note":"Sub-degree on Moon at any Kali-Yuga date (~2-5° residual max)","tradition_chain":"Āryabhaṭa(499) → Brahmagupta(628) → Bhāskara II(1150) → Mādhava(~1400) → Parameśvara(1430) → Nīlakaṇṭha(1501) → this","input":{"year":2021,"month":10,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2459500.770833,"kali_year":5123,"ahargana":1871035.2708,"sun":{"sidereal_longitude":174.9827,"rashi":6,"rashi_name":"Kanyā"},"moon":{"sidereal_longitude":261.4194,"rashi":9,"rashi_name":"Dhanu"},"tithi":{"number":8,"name":"Aṣṭamī","paksha":"Śukla","full_name":"Śukla Aṣṭamī","elongation_degrees":86.4367,"elapsed_within_tithi_degrees":2.4367},"nakshatra":{"number":20,"name":"Pūrva Āṣāḍhā","pada":3,"moon_longitude":261.4194,"elapsed_within_degrees":8.0861},"yoga":{"number":6,"name":"Atigaṇḍa","sum_longitude":76.4022},"karana":{"half_tithi_index":14,"name":"Viṣṭi"},"vara":{"number":5,"name":"Budhavāra (Wednesday)"}},"sky":{"method":"Sūrya-Siddhāntic Bhāskara-II 4-step iteration with atan2-based śīghra + varying peripheries + lunar latitude","engine_version":"3.0 (Pūrṇa — complete SS implementation)","tradition_sources":"Āryabhaṭīya 499 CE → SS Ch.1-5 Burgess 1860 → Siddhānta-Śiromaṇi Bhāskara II 1150 → Tantrasaṅgraha Nīlakaṇṭha 1501","input":{"year":2021,"month":10,"day":13,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2459500.770833,"ahargana":1871035.2708,"kali_year":5123,"ayanamsa_lahiri":24.1573,"grahas":{"sun":{"sidereal_longitude":175.77374099999997,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":14,"name":"Citrā","pada":1},"retrograde":false},"moon":{"sidereal_longitude":264.50944100000004,"rashi":{"number":9,"name":"Dhanu"},"nakshatra":{"number":20,"name":"Pūrva Āṣāḍhā","pada":4},"retrograde":false,"latitude":-2.7608},"mars":{"sidereal_longitude":173.82804099999998,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":14,"name":"Citrā","pada":1},"retrograde":false},"mercury":{"sidereal_longitude":168.631441,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":3},"retrograde":false},"jupiter":{"sidereal_longitude":298.193041,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":23,"name":"Dhaniṣṭhā","pada":2},"retrograde":true},"venus":{"sidereal_longitude":221.66464100000007,"rashi":{"number":8,"name":"Vṛścika"},"nakshatra":{"number":17,"name":"Anurādhā","pada":3},"retrograde":false},"saturn":{"sidereal_longitude":282.75934099999995,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":22,"name":"Śravaṇa","pada":1},"retrograde":false},"rahu":{"sidereal_longitude":43.5473,"rashi":{"number":2,"name":"Vṛṣabha"},"nakshatra":{"number":4,"name":"Rohiṇī","pada":2},"retrograde":false},"ketu":{"sidereal_longitude":223.5473,"rashi":{"number":8,"name":"Vṛścika"},"nakshatra":{"number":17,"name":"Anurādhā","pada":4},"retrograde":false}},"panchang":{"method":"Sūrya Siddhānta + Bhāskara-II iterative manda + Kerala-school (Mādhava-Nīlakaṇṭha) evection + variation + annual equation","engine_version":"2.0 (Kerala-school enhanced)","accuracy_note":"Sub-degree on Moon at any Kali-Yuga date (~2-5° residual max)","tradition_chain":"Āryabhaṭa(499) → Brahmagupta(628) → Bhāskara II(1150) → Mādhava(~1400) → Parameśvara(1430) → Nīlakaṇṭha(1501) → this","input":{"year":2021,"month":10,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2459500.770833,"kali_year":5123,"ahargana":1871035.2708,"sun":{"sidereal_longitude":174.9827,"rashi":6,"rashi_name":"Kanyā"},"moon":{"sidereal_longitude":261.4194,"rashi":9,"rashi_name":"Dhanu"},"tithi":{"number":8,"name":"Aṣṭamī","paksha":"Śukla","full_name":"Śukla Aṣṭamī","elongation_degrees":86.4367,"elapsed_within_tithi_degrees":2.4367},"nakshatra":{"number":20,"name":"Pūrva Āṣāḍhā","pada":3,"moon_longitude":261.4194,"elapsed_within_degrees":8.0861},"yoga":{"number":6,"name":"Atigaṇḍa","sum_longitude":76.4022},"karana":{"half_tithi_index":14,"name":"Viṣṭi"},"vara":{"number":5,"name":"Budhavāra (Wednesday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":-2.761,"elongation":86.437},"lunar":{"type":"lunar","occurs":false,"moon_latitude":-2.761,"opposition_distance":93.563}},"eclipse_window_40days":[]},"calendars":{"vikram_samvat":2078,"vikram_samvatsara":"Ānanda","saka_samvat":1943,"saka_samvatsara":"Plava","bengali_samvat":1428,"malayalam_era":1197,"nanakshahi_year":552,"lunar_month":"Āśvina","lunar_month_paksha_full":"Āśvina Śukla Pakṣa","solar_month":"Kanyā (Puraṭṭāsi)","ritu":"Śarad (Autumn)","display_summary":"Āśvina Śukla Aṣṭamī · Vikram 2078 Ānanda · Śaka 1943 Plava"},"festivals":[{"id":"durga-ashtami","name":"Mahā-Aṣṭamī (Durgā-Aṣṭamī)","name_sanskrit":"महाष्टमी","tradition":"Shakta","associated_deity":"Devī Durgā","significance":"8th day of Śāradīya Navrātri; Mahiṣāsura-mardinī kṣaṇa.","vrata":true,"detection":{"tithi_number":8,"tithi_paksha":"Śukla","lunar_month":"Āśvina"},"precedence":1},{"id":"kanya-sankranti","name":"Kanyā Saṅkrānti (Mahālaya begins)","name_sanskrit":"कन्या सङ्क्रान्ति","tradition":"Pan-Hindu","significance":"Sun enters Virgo; Mahālaya / Pitṛ-Pakṣa solar marker.","vrata":false,"detection":{"sun_rashi":"Kanyā"},"precedence":4}],"todays_walk":{"walk":{"id":"budha-walk","name":"Budha Walk","name_sanskrit":"बुध यात्रा","type":"graha","description":"Discrimination + BG 2.41 (vyavasāyātmikā buddhi).","step_count":6,"url":"/walk/budha-walk"},"reason":"Budhavāra (Wednesday) — its presiding graha's walk."},"cosmic_resonances":[{"historical_date":"-3137-12-25","event":"Bhīṣma's Mahaprasthan","chart_id":"bhishma","shared_marker":"same Śukla Aṣṭamī","url":"/day/-3137-12-25","relevance":0.5}]},"validity":{"eternal":false,"valid_from":"2021-10-13T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga October 13, 2021 CE · Vidhyamitra","description":"Vedic pañchāṅga for October 13, 2021 CE: Śukla Aṣṭamī · Pūrva Āṣāḍhā.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/2021-10-13","hreflang_alternates":{"en":"https://vidhyamitra.com/day/2021-10-13","sa":"https://sa.vidhyamitra.com/day/2021-10-13","hi":"https://hi.vidhyamitra.com/day/2021-10-13","x-default":"https://vidhyamitra.com/day/2021-10-13"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-14T08:22:33.329Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-14T08:22:33.329Z","pillar_versions":{"BOB-History":"Pūrṇa"}}}