{"id":"vidhyamitra:day:1981-07-13:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/1981-07-13","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"1981-07-13","date_display":"July 13, 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":7,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444798.770833,"kali_year":5083,"ahargana":1856333.2708,"sun":{"sidereal_longitude":86.6041,"rashi":3,"rashi_name":"Mithuna"},"moon":{"sidereal_longitude":218.3381,"rashi":8,"rashi_name":"Vṛścika"},"tithi":{"number":11,"name":"Ekādaśī","paksha":"Śukla","full_name":"Śukla Ekādaśī","elongation_degrees":131.7339,"elapsed_within_tithi_degrees":11.7339},"nakshatra":{"number":17,"name":"Anurādhā","pada":2,"moon_longitude":218.3381,"elapsed_within_degrees":5.0047},"yoga":{"number":23,"name":"Śubha","sum_longitude":304.9422},"karana":{"half_tithi_index":21,"name":"Viṣṭi"},"vara":{"number":3,"name":"Somavāra (Monday)"}},"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":7,"day":13,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2444798.770833,"ahargana":1856333.2708,"kali_year":5083,"ayanamsa_lahiri":23.595,"grahas":{"sun":{"sidereal_longitude":86.97736599999996,"rashi":{"number":3,"name":"Mithuna"},"nakshatra":{"number":7,"name":"Punarvasu","pada":3},"retrograde":false},"moon":{"sidereal_longitude":220.07976600000006,"rashi":{"number":8,"name":"Vṛścika"},"nakshatra":{"number":17,"name":"Anurādhā","pada":3},"retrograde":false,"latitude":4.0504},"mars":{"sidereal_longitude":63.03296599999999,"rashi":{"number":3,"name":"Mithuna"},"nakshatra":{"number":5,"name":"Mr̥gaśirā","pada":3},"retrograde":false},"mercury":{"sidereal_longitude":66.61236600000001,"rashi":{"number":3,"name":"Mithuna"},"nakshatra":{"number":5,"name":"Mr̥gaśirā","pada":4},"retrograde":false},"jupiter":{"sidereal_longitude":160.10616600000003,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":1},"retrograde":false},"venus":{"sidereal_longitude":112.720166,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":9,"name":"Aśleṣā","pada":2},"retrograde":false},"saturn":{"sidereal_longitude":160.305066,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":1},"retrograde":false},"rahu":{"sidereal_longitude":102.53,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":8,"name":"Puṣya","pada":3},"retrograde":false},"ketu":{"sidereal_longitude":282.53,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":22,"name":"Śravaṇa","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":1981,"month":7,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444798.770833,"kali_year":5083,"ahargana":1856333.2708,"sun":{"sidereal_longitude":86.6041,"rashi":3,"rashi_name":"Mithuna"},"moon":{"sidereal_longitude":218.3381,"rashi":8,"rashi_name":"Vṛścika"},"tithi":{"number":11,"name":"Ekādaśī","paksha":"Śukla","full_name":"Śukla Ekādaśī","elongation_degrees":131.7339,"elapsed_within_tithi_degrees":11.7339},"nakshatra":{"number":17,"name":"Anurādhā","pada":2,"moon_longitude":218.3381,"elapsed_within_degrees":5.0047},"yoga":{"number":23,"name":"Śubha","sum_longitude":304.9422},"karana":{"half_tithi_index":21,"name":"Viṣṭi"},"vara":{"number":3,"name":"Somavāra (Monday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":4.05,"elongation":131.734},"lunar":{"type":"lunar","occurs":false,"moon_latitude":4.05,"opposition_distance":48.266}},"eclipse_window_40days":[{"offset_days":4,"type":"lunar","occurs":true,"moon_latitude":1.092,"opposition_distance":2.128},{"offset_days":18,"type":"solar","occurs":true,"moon_latitude":0.181,"elongation":0.207}]},"calendars":{"vikram_samvat":2038,"vikram_samvatsara":"Bhāva","saka_samvat":1903,"saka_samvatsara":"Durmati","bengali_samvat":1388,"malayalam_era":1157,"nanakshahi_year":512,"lunar_month":"Āṣāḍha","lunar_month_paksha_full":"Āṣāḍha Śukla Pakṣa","solar_month":"Mithuna (Āni)","ritu":"Grīṣma (Summer)","display_summary":"Āṣāḍha Śukla Ekādaśī · Vikram 2038 Bhāva · Śaka 1903 Durmati"},"festivals":[{"id":"devshayani-ekadashi","name":"Devśayanī Ekādaśī","name_sanskrit":"देवशयनी एकादशी","tradition":"Vaishnava","associated_deity":"Bhagavān Viṣṇu","significance":"Bhagavān Viṣṇu enters yoga-nidrā; Cāturmāsya begins.","vrata":true,"detection":{"tithi_number":11,"tithi_paksha":"Śukla","lunar_month":"Āṣāḍha"},"precedence":3},{"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":"mithuna-sankranti","name":"Mithuna Saṅkrānti","name_sanskrit":"मिथुन सङ्क्रान्ति","tradition":"Pan-Hindu","significance":"Sun enters Gemini.","vrata":false,"detection":{"sun_rashi":"Mithuna"},"precedence":5}],"todays_walk":{"walk":{"id":"chandra-walk","name":"Candra Walk","name_sanskrit":"चन्द्र यात्रा","type":"graha","description":"Manas-control + BG 6.5-7.","step_count":5,"url":"/walk/chandra-walk"},"reason":"Somavāra (Monday) — its presiding graha's walk."},"cosmic_resonances":[]},"validity":{"eternal":false,"valid_from":"1981-07-13T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga July 13, 1981 CE · Vidhyamitra","description":"Vedic pañchāṅga for July 13, 1981 CE: Śukla Ekādaśī · Anurādhā.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/1981-07-13","hreflang_alternates":{"en":"https://vidhyamitra.com/day/1981-07-13","sa":"https://sa.vidhyamitra.com/day/1981-07-13","hi":"https://hi.vidhyamitra.com/day/1981-07-13","x-default":"https://vidhyamitra.com/day/1981-07-13"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-14T11:42:46.775Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-14T11:42:46.775Z","pillar_versions":{"BOB-History":"Pūrṇa"}}}