{"id":"vidhyamitra:day:1931-05-21:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/1931-05-21","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"1931-05-21","date_display":"May 21, 1931 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":1931,"month":5,"day":21,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2426482.770833,"kali_year":5033,"ahargana":1838017.2708,"sun":{"sidereal_longitude":36.2484,"rashi":2,"rashi_name":"Vṛṣabha"},"moon":{"sidereal_longitude":78.2133,"rashi":3,"rashi_name":"Mithuna"},"tithi":{"number":4,"name":"Caturthī","paksha":"Śukla","full_name":"Śukla Caturthī","elongation_degrees":41.9649,"elapsed_within_tithi_degrees":5.9649},"nakshatra":{"number":6,"name":"Ārdrā","pada":4,"moon_longitude":78.2133,"elapsed_within_degrees":11.5466},"yoga":{"number":9,"name":"Śūla","sum_longitude":114.4617},"karana":{"half_tithi_index":6,"name":"Vaṇija"},"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":1931,"month":5,"day":21,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2426482.770833,"ahargana":1838017.2708,"kali_year":5033,"ayanamsa_lahiri":22.8945,"grahas":{"sun":{"sidereal_longitude":36.14197200000001,"rashi":{"number":2,"name":"Vṛṣabha"},"nakshatra":{"number":3,"name":"Kṛttikā","pada":3},"retrograde":false},"moon":{"sidereal_longitude":77.49727200000001,"rashi":{"number":3,"name":"Mithuna"},"nakshatra":{"number":6,"name":"Ārdrā","pada":4},"retrograde":false,"latitude":4.4843},"mars":{"sidereal_longitude":117.59487200000001,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":9,"name":"Aśleṣā","pada":4},"retrograde":false},"mercury":{"sidereal_longitude":13.590671999999984,"rashi":{"number":1,"name":"Meṣa"},"nakshatra":{"number":2,"name":"Bharaṇī","pada":1},"retrograde":false},"jupiter":{"sidereal_longitude":85.901072,"rashi":{"number":3,"name":"Mithuna"},"nakshatra":{"number":7,"name":"Punarvasu","pada":2},"retrograde":false},"venus":{"sidereal_longitude":7.997371999999984,"rashi":{"number":1,"name":"Meṣa"},"nakshatra":{"number":1,"name":"Aśvinī","pada":3},"retrograde":false},"saturn":{"sidereal_longitude":270.543172,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":21,"name":"Uttara Āṣāḍhā","pada":2},"retrograde":true},"rahu":{"sidereal_longitude":352.9998,"rashi":{"number":12,"name":"Mīna"},"nakshatra":{"number":27,"name":"Revatī","pada":2},"retrograde":false},"ketu":{"sidereal_longitude":172.9998,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","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":1931,"month":5,"day":21,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2426482.770833,"kali_year":5033,"ahargana":1838017.2708,"sun":{"sidereal_longitude":36.2484,"rashi":2,"rashi_name":"Vṛṣabha"},"moon":{"sidereal_longitude":78.2133,"rashi":3,"rashi_name":"Mithuna"},"tithi":{"number":4,"name":"Caturthī","paksha":"Śukla","full_name":"Śukla Caturthī","elongation_degrees":41.9649,"elapsed_within_tithi_degrees":5.9649},"nakshatra":{"number":6,"name":"Ārdrā","pada":4,"moon_longitude":78.2133,"elapsed_within_degrees":11.5466},"yoga":{"number":9,"name":"Śūla","sum_longitude":114.4617},"karana":{"half_tithi_index":6,"name":"Vaṇija"},"vara":{"number":6,"name":"Guruvāra (Thursday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":4.484,"elongation":41.965},"lunar":{"type":"lunar","occurs":false,"moon_latitude":4.484,"opposition_distance":138.035}},"eclipse_window_40days":[]},"calendars":{"vikram_samvat":1988,"vikram_samvatsara":"Tāraṇa","saka_samvat":1853,"saka_samvatsara":"Prajāpati","bengali_samvat":1338,"malayalam_era":1107,"nanakshahi_year":462,"lunar_month":"Jyeṣṭha","lunar_month_paksha_full":"Jyeṣṭha Śukla Pakṣa","solar_month":"Vṛṣabha (Vaikāsi)","ritu":"Grīṣma (Summer)","display_summary":"Jyeṣṭha Śukla Caturthī · Vikram 1988 Tāraṇa · Śaka 1853 Prajāpati"},"festivals":[{"id":"vrishabha-sankranti","name":"Vṛṣabha Saṅkrānti","name_sanskrit":"वृषभ सङ्क्रान्ति","tradition":"Pan-Hindu","significance":"Sun enters Taurus.","vrata":false,"detection":{"sun_rashi":"Vṛṣabha"},"precedence":5},{"id":"vinayaka-chaturthi","name":"Vināyaka Caturthī (monthly)","name_sanskrit":"विनायक चतुर्थी","tradition":"Pan-Hindu","associated_deity":"Gaṇeśa","significance":"Monthly Śukla-pakṣa Caturthī; auspicious for new ventures.","vrata":true,"detection":{"tithi_number":4,"tithi_paksha":"Śukla"},"precedence":6}],"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":"1931-05-21T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga May 21, 1931 CE · Vidhyamitra","description":"Vedic pañchāṅga for May 21, 1931 CE: Śukla Caturthī · Ārdrā.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/1931-05-21","hreflang_alternates":{"en":"https://vidhyamitra.com/day/1931-05-21","sa":"https://sa.vidhyamitra.com/day/1931-05-21","hi":"https://hi.vidhyamitra.com/day/1931-05-21","x-default":"https://vidhyamitra.com/day/1931-05-21"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-14T06:11:19.422Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-14T06:11:19.422Z","pillar_versions":{"BOB-History":"Pūrṇa"}}}