{"id":"vidhyamitra:day:2087-09-13:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/2087-09-13","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"2087-09-13","date_display":"September 13, 2087 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":2087,"month":9,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2483576.770833,"kali_year":5189,"ahargana":1895111.2708,"sun":{"sidereal_longitude":144.5095,"rashi":5,"rashi_name":"Siṃha"},"moon":{"sidereal_longitude":327.4922,"rashi":11,"rashi_name":"Kumbha"},"tithi":{"number":16,"name":"Pratipada","paksha":"Kṛṣṇa","full_name":"Kṛṣṇa Pratipada","elongation_degrees":182.9827,"elapsed_within_tithi_degrees":2.9827},"nakshatra":{"number":25,"name":"Pūrva Bhādrapadā","pada":3,"moon_longitude":327.4922,"elapsed_within_degrees":7.4922},"yoga":{"number":9,"name":"Śūla","sum_longitude":112.0018},"karana":{"half_tithi_index":30,"name":"Bālava"},"vara":{"number":1,"name":"Śanivāra (Saturday)"}},"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":2087,"month":9,"day":13,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2483576.770833,"ahargana":1895111.2708,"kali_year":5189,"ayanamsa_lahiri":25.0781,"grahas":{"sun":{"sidereal_longitude":145.441961,"rashi":{"number":5,"name":"Siṃha"},"nakshatra":{"number":11,"name":"Pūrva Phalgunī","pada":4},"retrograde":false},"moon":{"sidereal_longitude":329.91006100000004,"rashi":{"number":11,"name":"Kumbha"},"nakshatra":{"number":25,"name":"Pūrva Bhādrapadā","pada":3},"retrograde":false,"latitude":3.9115},"mars":{"sidereal_longitude":170.55886099999998,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":4},"retrograde":false},"mercury":{"sidereal_longitude":170.999461,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":4},"retrograde":false},"jupiter":{"sidereal_longitude":151.446861,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":12,"name":"Uttara Phalgunī","pada":2},"retrograde":false},"venus":{"sidereal_longitude":100.185161,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":8,"name":"Puṣya","pada":3},"retrograde":false},"saturn":{"sidereal_longitude":17.64196099999998,"rashi":{"number":1,"name":"Meṣa"},"nakshatra":{"number":2,"name":"Bharaṇī","pada":2},"retrograde":true},"rahu":{"sidereal_longitude":207.885,"rashi":{"number":7,"name":"Tulā"},"nakshatra":{"number":16,"name":"Viśākhā","pada":3},"retrograde":false},"ketu":{"sidereal_longitude":27.885,"rashi":{"number":1,"name":"Meṣa"},"nakshatra":{"number":3,"name":"Kṛttikā","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":2087,"month":9,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2483576.770833,"kali_year":5189,"ahargana":1895111.2708,"sun":{"sidereal_longitude":144.5095,"rashi":5,"rashi_name":"Siṃha"},"moon":{"sidereal_longitude":327.4922,"rashi":11,"rashi_name":"Kumbha"},"tithi":{"number":16,"name":"Pratipada","paksha":"Kṛṣṇa","full_name":"Kṛṣṇa Pratipada","elongation_degrees":182.9827,"elapsed_within_tithi_degrees":2.9827},"nakshatra":{"number":25,"name":"Pūrva Bhādrapadā","pada":3,"moon_longitude":327.4922,"elapsed_within_degrees":7.4922},"yoga":{"number":9,"name":"Śūla","sum_longitude":112.0018},"karana":{"half_tithi_index":30,"name":"Bālava"},"vara":{"number":1,"name":"Śanivāra (Saturday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":3.911,"elongation":177.017},"lunar":{"type":"lunar","occurs":false,"moon_latitude":3.911,"opposition_distance":2.983}},"eclipse_window_40days":[]},"calendars":{"vikram_samvat":2144,"vikram_samvatsara":"Raudra","saka_samvat":2009,"saka_samvatsara":"Plavaṅga","bengali_samvat":1494,"malayalam_era":1263,"nanakshahi_year":618,"lunar_month":"Bhādrapada","lunar_month_paksha_full":"Bhādrapada Kṛṣṇa Pakṣa","solar_month":"Siṃha (Āvaṇi)","ritu":"Varṣā (Monsoon)","display_summary":"Bhādrapada Kṛṣṇa Pratipada · Vikram 2144 Raudra · Śaka 2009 Plavaṅga"},"festivals":[{"id":"pitra-paksha-start","name":"Pitṛ-Pakṣa Start","name_sanskrit":"पितृ पक्ष आरम्भ","tradition":"Pan-Hindu","associated_deity":"Pitṛ-gaṇa","significance":"Begin 16-day śrāddha period for ancestors. Bhādrapada Pūrṇimā next-day.","vrata":true,"detection":{"tithi_number":16,"tithi_paksha":"Kṛṣṇa","lunar_month":"Bhādrapada"},"precedence":2},{"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":"shani-walk","name":"Śani Walk","name_sanskrit":"शनि यात्रा","type":"graha","description":"Tapas + endurance + BG 17.14-19.","step_count":7,"url":"/walk/shani-walk"},"reason":"Śanivāra (Saturday) — its presiding graha's walk."},"cosmic_resonances":[]},"validity":{"eternal":false,"valid_from":"2087-09-13T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga September 13, 2087 CE · Vidhyamitra","description":"Vedic pañchāṅga for September 13, 2087 CE: Kṛṣṇa Pratipada · Pūrva Bhādrapadā.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/2087-09-13","hreflang_alternates":{"en":"https://vidhyamitra.com/day/2087-09-13","sa":"https://sa.vidhyamitra.com/day/2087-09-13","hi":"https://hi.vidhyamitra.com/day/2087-09-13","x-default":"https://vidhyamitra.com/day/2087-09-13"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-14T22:50:16.116Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-14T22:50:16.116Z","pillar_versions":{"Sūrya-Siddhānta":"Pūrṇa"}}}