{"id":"vidhyamitra:day:1981-09-12:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/1981-09-12","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"1981-09-12","date_display":"September 12, 1981 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":1981,"month":9,"day":12,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444859.770833,"kali_year":5083,"ahargana":1856394.2708,"sun":{"sidereal_longitude":144.925,"rashi":5,"rashi_name":"Siṃha"},"moon":{"sidereal_longitude":297.8538,"rashi":10,"rashi_name":"Makara"},"tithi":{"number":13,"name":"Trayodaśī","paksha":"Śukla","full_name":"Śukla Trayodaśī","elongation_degrees":152.9288,"elapsed_within_tithi_degrees":8.9288},"nakshatra":{"number":23,"name":"Dhaniṣṭhā","pada":2,"moon_longitude":297.8538,"elapsed_within_degrees":4.5205},"yoga":{"number":7,"name":"Sukarma","sum_longitude":82.7789},"karana":{"half_tithi_index":25,"name":"Taitila"},"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":1981,"month":9,"day":12,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2444859.770833,"ahargana":1856394.2708,"kali_year":5083,"ayanamsa_lahiri":23.5973,"grahas":{"sun":{"sidereal_longitude":145.601335,"rashi":{"number":5,"name":"Siṃha"},"nakshatra":{"number":11,"name":"Pūrva Phalgunī","pada":4},"retrograde":false},"moon":{"sidereal_longitude":298.7416350000001,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":23,"name":"Dhaniṣṭhā","pada":2},"retrograde":false,"latitude":-1.4307},"mars":{"sidereal_longitude":102.95043499999997,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":8,"name":"Puṣya","pada":3},"retrograde":false},"mercury":{"sidereal_longitude":169.698535,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":3},"retrograde":false},"jupiter":{"sidereal_longitude":170.62663500000008,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":4},"retrograde":false},"venus":{"sidereal_longitude":185.60043500000006,"rashi":{"number":7,"name":"Tulā"},"nakshatra":{"number":14,"name":"Citrā","pada":4},"retrograde":false},"saturn":{"sidereal_longitude":166.00993500000004,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":2},"retrograde":false},"rahu":{"sidereal_longitude":99.2979,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":8,"name":"Puṣya","pada":2},"retrograde":false},"ketu":{"sidereal_longitude":279.2979,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":21,"name":"Uttara Āṣāḍhā","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":1981,"month":9,"day":12,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444859.770833,"kali_year":5083,"ahargana":1856394.2708,"sun":{"sidereal_longitude":144.925,"rashi":5,"rashi_name":"Siṃha"},"moon":{"sidereal_longitude":297.8538,"rashi":10,"rashi_name":"Makara"},"tithi":{"number":13,"name":"Trayodaśī","paksha":"Śukla","full_name":"Śukla Trayodaśī","elongation_degrees":152.9288,"elapsed_within_tithi_degrees":8.9288},"nakshatra":{"number":23,"name":"Dhaniṣṭhā","pada":2,"moon_longitude":297.8538,"elapsed_within_degrees":4.5205},"yoga":{"number":7,"name":"Sukarma","sum_longitude":82.7789},"karana":{"half_tithi_index":25,"name":"Taitila"},"vara":{"number":1,"name":"Śanivāra (Saturday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":-1.431,"elongation":152.929},"lunar":{"type":"lunar","occurs":false,"moon_latitude":-1.431,"opposition_distance":27.071}},"eclipse_window_40days":[]},"calendars":{"vikram_samvat":2038,"vikram_samvatsara":"Bhāva","saka_samvat":1903,"saka_samvatsara":"Durmati","bengali_samvat":1388,"malayalam_era":1157,"nanakshahi_year":512,"lunar_month":"Bhādrapada","lunar_month_paksha_full":"Bhādrapada Śukla Pakṣa","solar_month":"Siṃha (Āvaṇi)","ritu":"Varṣā (Monsoon)","display_summary":"Bhādrapada Śukla Trayodaśī · Vikram 2038 Bhāva · Śaka 1903 Durmati"},"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},{"id":"pradosha-vrata","name":"Pradoṣa Vrata","name_sanskrit":"प्रदोष व्रत","tradition":"Shaiva","associated_deity":"Śiva","significance":"Twilight worship of Śiva on Trayodaśī.","vrata":true,"detection":{"any_of":[{"tithi_number":13},{"tithi_number":28}]},"precedence":7}],"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":"1981-09-12T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga September 12, 1981 CE · Vidhyamitra","description":"Vedic pañchāṅga for September 12, 1981 CE: Śukla Trayodaśī · Dhaniṣṭhā.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/1981-09-12","hreflang_alternates":{"en":"https://vidhyamitra.com/day/1981-09-12","sa":"https://sa.vidhyamitra.com/day/1981-09-12","hi":"https://hi.vidhyamitra.com/day/1981-09-12","x-default":"https://vidhyamitra.com/day/1981-09-12"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-14T06:24:41.456Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-14T06:24:41.456Z","pillar_versions":{"BOB-History":"Pūrṇa"}}}