{"id":"vidhyamitra:day:1980-12-18:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/1980-12-18","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"1980-12-18","date_display":"December 18, 1980 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":1980,"month":12,"day":18,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444591.770833,"kali_year":5082,"ahargana":1856126.2708,"sun":{"sidereal_longitude":242.3816,"rashi":9,"rashi_name":"Dhanu"},"moon":{"sidereal_longitude":14.1901,"rashi":1,"rashi_name":"Meṣa"},"tithi":{"number":11,"name":"Ekādaśī","paksha":"Śukla","full_name":"Śukla Ekādaśī","elongation_degrees":131.8084,"elapsed_within_tithi_degrees":11.8084},"nakshatra":{"number":2,"name":"Bharaṇī","pada":1,"moon_longitude":14.1901,"elapsed_within_degrees":0.8567},"yoga":{"number":20,"name":"Śiva","sum_longitude":256.5717},"karana":{"half_tithi_index":21,"name":"Viṣṭi"},"vara":{"number":6,"name":"Guruvāra (Thursday)"}},"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":1980,"month":12,"day":18,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2444591.770833,"ahargana":1856126.2708,"kali_year":5082,"ayanamsa_lahiri":23.5871,"grahas":{"sun":{"sidereal_longitude":242.69237499999997,"rashi":{"number":9,"name":"Dhanu"},"nakshatra":{"number":19,"name":"Mūla","pada":1},"retrograde":false},"moon":{"sidereal_longitude":12.07147500000002,"rashi":{"number":1,"name":"Meṣa"},"nakshatra":{"number":1,"name":"Aśvinī","pada":4},"retrograde":false,"latitude":-4.4406},"mars":{"sidereal_longitude":266.67657499999996,"rashi":{"number":9,"name":"Dhanu"},"nakshatra":{"number":21,"name":"Uttara Āṣāḍhā","pada":1},"retrograde":false},"mercury":{"sidereal_longitude":235.45047499999998,"rashi":{"number":8,"name":"Vṛścika"},"nakshatra":{"number":18,"name":"Jyeṣṭhā","pada":3},"retrograde":false},"jupiter":{"sidereal_longitude":164.67767500000002,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":2},"retrograde":false},"venus":{"sidereal_longitude":216.41607499999998,"rashi":{"number":8,"name":"Vṛścika"},"nakshatra":{"number":17,"name":"Anurādhā","pada":1},"retrograde":false},"saturn":{"sidereal_longitude":165.059075,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":2},"retrograde":false},"rahu":{"sidereal_longitude":113.4979,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":9,"name":"Āśleṣā","pada":3},"retrograde":false},"ketu":{"sidereal_longitude":293.4979,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":23,"name":"Dhaniṣṭhā","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":1980,"month":12,"day":18,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444591.770833,"kali_year":5082,"ahargana":1856126.2708,"sun":{"sidereal_longitude":242.3816,"rashi":9,"rashi_name":"Dhanu"},"moon":{"sidereal_longitude":14.1901,"rashi":1,"rashi_name":"Meṣa"},"tithi":{"number":11,"name":"Ekādaśī","paksha":"Śukla","full_name":"Śukla Ekādaśī","elongation_degrees":131.8084,"elapsed_within_tithi_degrees":11.8084},"nakshatra":{"number":2,"name":"Bharaṇī","pada":1,"moon_longitude":14.1901,"elapsed_within_degrees":0.8567},"yoga":{"number":20,"name":"Śiva","sum_longitude":256.5717},"karana":{"half_tithi_index":21,"name":"Viṣṭi"},"vara":{"number":6,"name":"Guruvāra (Thursday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":-4.441,"elongation":131.808},"lunar":{"type":"lunar","occurs":false,"moon_latitude":-4.441,"opposition_distance":48.192}},"eclipse_window_40days":[]},"calendars":{"vikram_samvat":2037,"vikram_samvatsara":"Śrīmukha","saka_samvat":1902,"saka_samvatsara":"Raudra","bengali_samvat":1387,"malayalam_era":1156,"nanakshahi_year":511,"lunar_month":"Pauṣa","lunar_month_paksha_full":"Pauṣa Śukla Pakṣa","solar_month":"Dhanus (Mārgaḻi)","ritu":"Hemanta (Pre-winter)","display_summary":"Pauṣa Śukla Ekādaśī · Vikram 2037 Śrīmukha · Śaka 1902 Raudra"},"festivals":[{"id":"putrada-ekadashi","name":"Pauṣa Putradā Ekādaśī","name_sanskrit":"पौष पुत्रदा एकादशी","tradition":"Vaishnava","associated_deity":"Bhagavān Viṣṇu","significance":"Ekādaśī granting putra-prāpti.","vrata":true,"detection":{"tithi_number":11,"tithi_paksha":"Śukla","lunar_month":"Pauṣa"},"precedence":4},{"id":"lohri","name":"Lohri","name_sanskrit":"लोहड़ी","tradition":"Regional","significance":"Punjab harvest festival; eve of Makara Saṅkrānti. (Approximated as 13/14 January annually; correct via Sun in Dhanu/Makara cusp.)","vrata":false,"detection":{"sun_rashi":"Dhanu"},"precedence":4},{"id":"ekadashi","name":"Ekādaśī","name_sanskrit":"एकादशी","tradition":"Vaishnava","associated_deity":"Bhagavān Viṣṇu","significance":"Sacred to Bhagavān Viṣṇu; vrata for purification.","vrata":true,"detection":{"any_of":[{"tithi_number":11},{"tithi_number":26}]},"precedence":5},{"id":"dhanu-sankranti","name":"Dhanu Saṅkrānti","name_sanskrit":"धनु सङ्क्रान्ति","tradition":"Pan-Hindu","significance":"Sun enters Sagittarius; Dhanu-māsa (Khara-māsa).","vrata":false,"detection":{"sun_rashi":"Dhanu"},"precedence":5}],"todays_walk":{"walk":{"id":"guru-walk","name":"Bṛhaspati Walk","name_sanskrit":"गुरु यात्रा","type":"graha","description":"Wisdom transmission + BG 4.34.","step_count":8,"url":"/walk/guru-walk"},"reason":"Guruvāra (Thursday) — its presiding graha's walk."},"cosmic_resonances":[]},"validity":{"eternal":false,"valid_from":"1980-12-18T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga December 18, 1980 CE · Vidhyamitra","description":"Vedic pañchāṅga for December 18, 1980 CE: Śukla Ekādaśī · Bharaṇī.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/1980-12-18","hreflang_alternates":{"en":"https://vidhyamitra.com/day/1980-12-18","sa":"https://sa.vidhyamitra.com/day/1980-12-18","hi":"https://hi.vidhyamitra.com/day/1980-12-18","x-default":"https://vidhyamitra.com/day/1980-12-18"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-14T18:36:05.795Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-14T18:36:05.795Z","pillar_versions":{"Sūrya-Siddhānta":"Pūrṇa"}}}