{"id":"vidhyamitra:day:2171-09-13:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/2171-09-13","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"2171-09-13","date_display":"September 13, 2171 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":2171,"month":9,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2514256.770833,"kali_year":5273,"ahargana":1925791.2708,"sun":{"sidereal_longitude":142.8265,"rashi":5,"rashi_name":"Siṃha"},"moon":{"sidereal_longitude":309.4068,"rashi":11,"rashi_name":"Kumbha"},"tithi":{"number":14,"name":"Caturdaśī","paksha":"Śukla","full_name":"Śukla Caturdaśī","elongation_degrees":166.5803,"elapsed_within_tithi_degrees":10.5803},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":1,"moon_longitude":309.4068,"elapsed_within_degrees":2.7402},"yoga":{"number":7,"name":"Sukarma","sum_longitude":92.2334},"karana":{"half_tithi_index":27,"name":"Vaṇija"},"vara":{"number":0,"name":"Śukravāra (Friday)"}},"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":2171,"month":9,"day":13,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2514256.770833,"ahargana":1925791.2708,"kali_year":5273,"ayanamsa_lahiri":26.2515,"grahas":{"sun":{"sidereal_longitude":143.95946000000004,"rashi":{"number":5,"name":"Siṃha"},"nakshatra":{"number":11,"name":"Pūrva Phalgunī","pada":4},"retrograde":false},"moon":{"sidereal_longitude":309.46885999999995,"rashi":{"number":11,"name":"Kumbha"},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":1},"retrograde":false,"latitude":-4.3008},"mars":{"sidereal_longitude":103.38936000000001,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":8,"name":"Puṣya","pada":4},"retrograde":false},"mercury":{"sidereal_longitude":157.97046,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":12,"name":"Uttara Phalgunī","pada":4},"retrograde":false},"jupiter":{"sidereal_longitude":172.51346,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":4},"retrograde":false},"venus":{"sidereal_longitude":160.99216,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":1},"retrograde":false},"saturn":{"sidereal_longitude":316.79736,"rashi":{"number":11,"name":"Kumbha"},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":4},"retrograde":true},"rahu":{"sidereal_longitude":22.3109,"rashi":{"number":1,"name":"Meṣa"},"nakshatra":{"number":2,"name":"Bharaṇī","pada":3},"retrograde":false},"ketu":{"sidereal_longitude":202.3109,"rashi":{"number":7,"name":"Tulā"},"nakshatra":{"number":16,"name":"Viśākhā","pada":1},"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":2171,"month":9,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2514256.770833,"kali_year":5273,"ahargana":1925791.2708,"sun":{"sidereal_longitude":142.8265,"rashi":5,"rashi_name":"Siṃha"},"moon":{"sidereal_longitude":309.4068,"rashi":11,"rashi_name":"Kumbha"},"tithi":{"number":14,"name":"Caturdaśī","paksha":"Śukla","full_name":"Śukla Caturdaśī","elongation_degrees":166.5803,"elapsed_within_tithi_degrees":10.5803},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":1,"moon_longitude":309.4068,"elapsed_within_degrees":2.7402},"yoga":{"number":7,"name":"Sukarma","sum_longitude":92.2334},"karana":{"half_tithi_index":27,"name":"Vaṇija"},"vara":{"number":0,"name":"Śukravāra (Friday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":-4.301,"elongation":166.58},"lunar":{"type":"lunar","occurs":false,"moon_latitude":-4.301,"opposition_distance":13.42}},"eclipse_window_40days":[]},"calendars":{"vikram_samvat":2228,"vikram_samvatsara":"Tāraṇa","saka_samvat":2093,"saka_samvatsara":"Prajāpati","bengali_samvat":1578,"malayalam_era":1347,"nanakshahi_year":702,"lunar_month":"Bhādrapada","lunar_month_paksha_full":"Bhādrapada Śukla Pakṣa","solar_month":"Siṃha (Āvaṇi)","ritu":"Varṣā (Monsoon)","display_summary":"Bhādrapada Śukla Caturdaśī · Vikram 2228 Tāraṇa · Śaka 2093 Prajāpati"},"festivals":[{"id":"simha-sankranti","name":"Siṁha Saṅkrānti","name_sanskrit":"सिंह सङ्क्रान्ति","tradition":"Pan-Hindu","significance":"Sun enters Leo.","vrata":false,"detection":{"sun_rashi":"Siṃha"},"precedence":5}],"todays_walk":{"walk":{"id":"shukra-walk","name":"Śukra Walk","name_sanskrit":"शुक्र यात्रा","type":"graha","description":"Beauty + creativity in dharma + BG 10.36.","step_count":5,"url":"/walk/shukra-walk"},"reason":"Śukravāra (Friday) — its presiding graha's walk."},"cosmic_resonances":[]},"validity":{"eternal":false,"valid_from":"2171-09-13T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga September 13, 2171 CE · Vidhyamitra","description":"Vedic pañchāṅga for September 13, 2171 CE: Śukla Caturdaśī · Śatabhiṣā.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/2171-09-13","hreflang_alternates":{"en":"https://vidhyamitra.com/day/2171-09-13","sa":"https://sa.vidhyamitra.com/day/2171-09-13","hi":"https://hi.vidhyamitra.com/day/2171-09-13","x-default":"https://vidhyamitra.com/day/2171-09-13"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-21T15:24:24.307Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-21T15:24:24.307Z","pillar_versions":{"Sūrya-Siddhānta":"Pūrṇa"}}}