{"id":"vidhyamitra:city-day:surat:1981-01-13:en","page_class":"VM-CD-city-day","url":"https://vidhyamitra.com/city/surat/1981-01-13","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"1981-01-13","date_display":"January 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":1,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444617.770833,"kali_year":5082,"ahargana":1856152.2708,"sun":{"sidereal_longitude":269.1023,"rashi":9,"rashi_name":"Dhanu"},"moon":{"sidereal_longitude":354.5831,"rashi":12,"rashi_name":"Mīna"},"tithi":{"number":8,"name":"Aṣṭamī","paksha":"Śukla","full_name":"Śukla Aṣṭamī","elongation_degrees":85.4807,"elapsed_within_tithi_degrees":1.4807},"nakshatra":{"number":27,"name":"Revatī","pada":3,"moon_longitude":354.5831,"elapsed_within_degrees":7.9164},"yoga":{"number":20,"name":"Śiva","sum_longitude":263.6854},"karana":{"half_tithi_index":14,"name":"Viṣṭi"},"vara":{"number":4,"name":"Maṅgalavāra (Tuesday)"}},"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":1,"day":13,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2444617.770833,"ahargana":1856152.2708,"kali_year":5082,"ayanamsa_lahiri":23.5881,"grahas":{"sun":{"sidereal_longitude":269.18438100000003,"rashi":{"number":9,"name":"Dhanu"},"nakshatra":{"number":21,"name":"Uttara Āṣāḍhā","pada":1},"retrograde":false},"moon":{"sidereal_longitude":354.117681,"rashi":{"number":12,"name":"Mīna"},"nakshatra":{"number":27,"name":"Revatī","pada":3},"retrograde":false,"latitude":-3.9893},"mars":{"sidereal_longitude":287.036781,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":22,"name":"Śravaṇa","pada":3},"retrograde":false},"mercury":{"sidereal_longitude":277.37348099999997,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":21,"name":"Uttara Āṣāḍhā","pada":4},"retrograde":false},"jupiter":{"sidereal_longitude":166.62898100000007,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":2},"retrograde":false},"venus":{"sidereal_longitude":248.882381,"rashi":{"number":9,"name":"Dhanu"},"nakshatra":{"number":19,"name":"Mūla","pada":3},"retrograde":false},"saturn":{"sidereal_longitude":165.93158100000005,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":13,"name":"Hasta","pada":2},"retrograde":false},"rahu":{"sidereal_longitude":112.1203,"rashi":{"number":4,"name":"Karka"},"nakshatra":{"number":9,"name":"Āśleṣā","pada":2},"retrograde":false},"ketu":{"sidereal_longitude":292.1203,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":22,"name":"Śravaṇa","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":1,"day":13,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444617.770833,"kali_year":5082,"ahargana":1856152.2708,"sun":{"sidereal_longitude":269.1023,"rashi":9,"rashi_name":"Dhanu"},"moon":{"sidereal_longitude":354.5831,"rashi":12,"rashi_name":"Mīna"},"tithi":{"number":8,"name":"Aṣṭamī","paksha":"Śukla","full_name":"Śukla Aṣṭamī","elongation_degrees":85.4807,"elapsed_within_tithi_degrees":1.4807},"nakshatra":{"number":27,"name":"Revatī","pada":3,"moon_longitude":354.5831,"elapsed_within_degrees":7.9164},"yoga":{"number":20,"name":"Śiva","sum_longitude":263.6854},"karana":{"half_tithi_index":14,"name":"Viṣṭi"},"vara":{"number":4,"name":"Maṅgalavāra (Tuesday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":-3.989,"elongation":85.481},"lunar":{"type":"lunar","occurs":false,"moon_latitude":-3.989,"opposition_distance":94.519}},"eclipse_window_40days":[{"offset_days":7,"type":"lunar","occurs":true,"moon_latitude":-1.332,"opposition_distance":1.776}]},"city":{"slug":"surat","name":"Surat, Gujarat","lat":21.1702,"lon":72.8311,"tz_offset_hours":5.5,"state":"Gujarat","country":"IN","tier":"mega","elevation_m":13},"tier2":{"city":{"slug":"surat","name":"Surat, Gujarat","lat":21.1702,"lon":72.8311,"tz_offset_hours":5.5,"state":"Gujarat","country":"IN","tier":"mega","elevation_m":13},"sunriseLocal":"07:19","sunsetLocal":"18:16","solarNoonLocal":"12:47","dayLengthHours":10.958548268162943,"dayLengthDisplay":"10 Hours 57 Mins 31 Secs","nightLengthDisplay":"13 Hours 02 Mins 29 Secs","moonriseLocal":"12:14","moonsetLocal":"00:40","rahuKala":{"name":"Rāhu Kāla","start":"15:32","end":"16:54","startHours":15.528162591896962,"endHours":16.89798112541733,"quality":"inauspicious"},"yamaganda":{"name":"Yamaganda","start":"10:03","end":"11:25","startHours":10.04888845781549,"endHours":11.41870699133586,"quality":"inauspicious"},"gulika":{"name":"Gulika Kāla","start":"12:47","end":"14:10","startHours":12.788525524856226,"endHours":14.158344058376596,"quality":"inauspicious"},"durMuhurta":[{"name":"Dur Muhūrta","start":"09:52","end":"10:14","startHours":9.866245986679441,"endHours":10.23153092895154,"quality":"avoid"}],"varjyam":{"name":"Varjyam","start":"07:46","end":"08:03","startHours":7.765857568614878,"endHours":8.058085522432556,"quality":"avoid"},"abhijit":{"name":"Abhijit Muhūrta","start":"12:25","end":"13:09","startHours":12.423240582584128,"endHours":13.153810467128324,"quality":"auspicious"},"brahmaMuhurta":{"name":"Brahma Muhūrta","start":"05:51","end":"06:35","startHours":5.848111621686363,"endHours":6.578681506230559,"quality":"auspicious"},"pratahSandhya":{"name":"Prātaḥ Sandhyā","start":"06:24","end":"07:19","startHours":6.39603903509451,"endHours":7.309251390774755,"quality":"auspicious"},"vijayaMuhurta":{"name":"Vijaya Muhūrta","start":"14:37","end":"15:21","startHours":14.614950236216718,"endHours":15.345520120760915,"quality":"auspicious"},"godhuliMuhurta":{"name":"Godhūli Muhūrta","start":"18:04","end":"18:28","startHours":18.067799658937698,"endHours":18.467799658937697,"quality":"auspicious"},"sayahnaSandhya":{"name":"Sāyāhna Sandhyā","start":"18:16","end":"18:43","startHours":18.267799658937697,"endHours":18.72440583677782,"quality":"auspicious"},"amritKala":{"name":"Amṛta Kāla","start":"18:01","end":"19:46","startHours":18.017799658937697,"endHours":19.767799658937697,"quality":"auspicious"},"nishitaMuhurta":{"name":"Niśīta Muhūrta","start":"00:25","end":"01:09","startHours":24.42324058258413,"endHours":25.153810467128324,"quality":"auspicious"},"dayChoghadiyas":[{"name":"Roga","start":"07:19","end":"08:41","startHours":7.309251390774755,"endHours":8.679069924295124,"quality":"inauspicious"},{"name":"Udveg","start":"08:41","end":"10:03","startHours":8.679069924295124,"endHours":10.04888845781549,"quality":"inauspicious"},{"name":"Chala","start":"10:03","end":"11:25","startHours":10.04888845781549,"endHours":11.41870699133586,"quality":"neutral"},{"name":"Labha","start":"11:25","end":"12:47","startHours":11.41870699133586,"endHours":12.788525524856226,"quality":"auspicious"},{"name":"Amṛta","start":"12:47","end":"14:10","startHours":12.788525524856226,"endHours":14.158344058376596,"quality":"auspicious"},{"name":"Kāla","start":"14:10","end":"15:32","startHours":14.158344058376596,"endHours":15.528162591896962,"quality":"inauspicious"},{"name":"Śubha","start":"15:32","end":"16:54","startHours":15.528162591896962,"endHours":16.89798112541733,"quality":"auspicious"},{"name":"Roga","start":"16:54","end":"18:16","startHours":16.89798112541733,"endHours":18.267799658937697,"quality":"inauspicious"}],"nightChoghadiyas":[{"name":"Kāla","start":"18:16","end":"19:54","startHours":18.267799658937697,"endHours":19.89798112541733,"quality":"inauspicious"},{"name":"Śubha","start":"19:54","end":"21:32","startHours":19.89798112541733,"endHours":21.52816259189696,"quality":"auspicious"},{"name":"Roga","start":"21:32","end":"23:10","startHours":21.52816259189696,"endHours":23.158344058376592,"quality":"inauspicious"},{"name":"Udveg","start":"23:10","end":"00:47","startHours":23.158344058376592,"endHours":24.788525524856226,"quality":"inauspicious"},{"name":"Chala","start":"00:47","end":"02:25","startHours":24.788525524856226,"endHours":26.41870699133586,"quality":"neutral"},{"name":"Labha","start":"02:25","end":"04:03","startHours":26.41870699133586,"endHours":28.04888845781549,"quality":"auspicious"},{"name":"Amṛta","start":"04:03","end":"05:41","startHours":28.04888845781549,"endHours":29.67906992429512,"quality":"auspicious"},{"name":"Kāla","start":"05:41","end":"07:19","startHours":29.67906992429512,"endHours":31.309251390774754,"quality":"inauspicious"}],"horas":[{"name":"Hora 1","start":"07:19","end":"08:19","startHours":7.309251390774755,"endHours":8.309251390774754,"planetary_lord":"Mars"},{"name":"Hora 2","start":"08:19","end":"09:19","startHours":8.309251390774754,"endHours":9.309251390774754,"planetary_lord":"Jupiter"},{"name":"Hora 3","start":"09:19","end":"10:19","startHours":9.309251390774754,"endHours":10.309251390774754,"planetary_lord":"Saturn"},{"name":"Hora 4","start":"10:19","end":"11:19","startHours":10.309251390774754,"endHours":11.309251390774754,"planetary_lord":"Moon"},{"name":"Hora 5","start":"11:19","end":"12:19","startHours":11.309251390774754,"endHours":12.309251390774754,"planetary_lord":"Mercury"},{"name":"Hora 6","start":"12:19","end":"13:19","startHours":12.309251390774754,"endHours":13.309251390774754,"planetary_lord":"Venus"},{"name":"Hora 7","start":"13:19","end":"14:19","startHours":13.309251390774754,"endHours":14.309251390774754,"planetary_lord":"Sun"},{"name":"Hora 8","start":"14:19","end":"15:19","startHours":14.309251390774754,"endHours":15.309251390774754,"planetary_lord":"Mars"},{"name":"Hora 9","start":"15:19","end":"16:19","startHours":15.309251390774754,"endHours":16.309251390774754,"planetary_lord":"Jupiter"},{"name":"Hora 10","start":"16:19","end":"17:19","startHours":16.309251390774754,"endHours":17.309251390774754,"planetary_lord":"Saturn"},{"name":"Hora 11","start":"17:19","end":"18:19","startHours":17.309251390774754,"endHours":18.309251390774754,"planetary_lord":"Moon"},{"name":"Hora 12","start":"18:19","end":"19:19","startHours":18.309251390774754,"endHours":19.309251390774754,"planetary_lord":"Mercury"},{"name":"Hora 13","start":"19:19","end":"20:19","startHours":19.309251390774754,"endHours":20.309251390774754,"planetary_lord":"Venus"},{"name":"Hora 14","start":"20:19","end":"21:19","startHours":20.309251390774754,"endHours":21.309251390774754,"planetary_lord":"Sun"},{"name":"Hora 15","start":"21:19","end":"22:19","startHours":21.309251390774754,"endHours":22.309251390774754,"planetary_lord":"Mars"},{"name":"Hora 16","start":"22:19","end":"23:19","startHours":22.309251390774754,"endHours":23.309251390774754,"planetary_lord":"Jupiter"},{"name":"Hora 17","start":"23:19","end":"00:19","startHours":23.309251390774754,"endHours":24.309251390774754,"planetary_lord":"Saturn"},{"name":"Hora 18","start":"00:19","end":"01:19","startHours":24.309251390774754,"endHours":25.309251390774754,"planetary_lord":"Moon"},{"name":"Hora 19","start":"01:19","end":"02:19","startHours":25.309251390774754,"endHours":26.309251390774754,"planetary_lord":"Mercury"},{"name":"Hora 20","start":"02:19","end":"03:19","startHours":26.309251390774754,"endHours":27.309251390774754,"planetary_lord":"Venus"},{"name":"Hora 21","start":"03:19","end":"04:19","startHours":27.309251390774754,"endHours":28.309251390774754,"planetary_lord":"Sun"},{"name":"Hora 22","start":"04:19","end":"05:19","startHours":28.309251390774754,"endHours":29.309251390774754,"planetary_lord":"Mars"},{"name":"Hora 23","start":"05:19","end":"06:19","startHours":29.309251390774754,"endHours":30.309251390774754,"planetary_lord":"Jupiter"},{"name":"Hora 24","start":"06:19","end":"07:19","startHours":30.309251390774754,"endHours":31.309251390774754,"planetary_lord":"Saturn"}],"taraBala":{"favorable_nakshatras":["Aśvinī","Bharaṇī","Kṛttikā","Rohiṇī","Mṛgaśirā","Maghā","Pūrva Phalgunī","Uttara Phalgunī","Hasta","Citrā","Mūla","Pūrva Āṣāḍhā","Uttara Āṣāḍhā","Śravaṇa","Dhaniṣṭhā"],"unfavorable_nakshatras":["Ārdrā","Punarvasu","Puṣya","Aśleṣā","Svātī","Viśākhā","Anurādhā","Jyeṣṭhā","Śatabhiṣaj","Pūrva Bhādrapadā","Uttara Bhādrapadā","Revatī"],"nature":"Janma-tara if same nakshatra; favorable for 15 nakshatras"},"chandraBala":{"favorable_rashis":["Vṛṣabha","Siṃha","Kanyā","Dhanu","Makara","Mīna"],"unfavorable_rashis":["Meṣa","Mithuna","Karka","Tulā","Vṛścika","Kumbha"]},"dishaShool":"North (Uttara)","chandraVasa":"South-West","rahuVasa":"North","anandadiYoga":{"name":"Dhvaja","quality":"Auspicious"},"tropicalRitu":"Hemanta (Pre-winter) (tropical)","vedicRitu":"Hemanta (Pre-winter)","tropicalAyana":"Uttarāyaṇa","vedicAyana":"Dakṣiṇāyana","meta":{"method":"BOB-History Sūrya-Siddhānta + Vidhyamitra Tier-2 spherical localization","declination":-21.51402002668385,"eotMinutes":-8.635931491373626,"ayanamsa":23.5881}},"calendars":{"vikram_samvat":2038,"vikram_samvatsara":"Bhāva","saka_samvat":1903,"saka_samvatsara":"Durmati","bengali_samvat":1388,"malayalam_era":1157,"nanakshahi_year":512,"lunar_month":"Pauṣa","lunar_month_paksha_full":"Pauṣa Śukla Pakṣa","lunar_month_system":"purnimanta","lunar_month_purnimanta":"Pauṣa","lunar_month_amanta":"Pauṣa","lunar_month_is_adhika":false,"lunar_month_purnimanta_is_adhika":false,"lunar_month_amanta_is_adhika":false,"solar_month":"Dhanus (Mārgaḻi)","ritu":"Hemanta (Pre-winter)","display_summary":"Pauṣa Śukla Aṣṭamī · Vikram 2038 Bhāva · Śaka 1903 Durmati"},"festivals":[{"id":"lohri","name":"Lohri","name_sanskrit":"लोहड़ी","tradition":"Regional","significance":"Punjab harvest festival; eve of Makara Saṅkrānti.","vrata":false,"detection":{"sun_rashi_eve_of_ingress":"Makara"},"precedence":4}],"todays_walk":{"walk":{"id":"mangala-walk","name":"Maṅgala Walk","name_sanskrit":"मङ्गल यात्रा","type":"graha","description":"Right action + BG 2.31-38 (kṣatriya-dharma).","step_count":7,"url":"/walk/mangala-walk"},"reason":"Maṅgalavāra (Tuesday) — its presiding graha's walk."},"cosmic_resonances":[{"historical_date":"-3137-12-25","event":"Bhīṣma's Mahaprasthan","chart_id":"bhishma","shared_marker":"same Śukla Aṣṭamī","url":"/day/-3137-12-25","relevance":0.5}]},"validity":{"eternal":false,"location_specific":"surat"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate + Vidhyamitra Tier-2 layer"},"seo":{"title":"Pañchāṅga January 13, 1981 CE · Surat, Gujarat · Vidhyamitra","description":"January 13, 1981 CE for Surat, Gujarat: Śukla Aṣṭamī, sūryodaya 07:19, sūryāsta 18:16.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/city/surat/1981-01-13","hreflang_alternates":{"en":"https://vidhyamitra.com/city/surat/1981-01-13","sa":"https://sa.vidhyamitra.com/city/surat/1981-01-13","hi":"https://hi.vidhyamitra.com/city/surat/1981-01-13","x-default":"https://vidhyamitra.com/city/surat/1981-01-13"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-06-02T13:59:30.728Z","verification":{"type":"multi-marker","confidence":"canonical"}},{"pillar":"Vidhyamitra-Tier2","pillar_version":"0.1.0","method":"Spherical astronomy + Lahiri ayanamsa + standard solar declination + EoT correction","retrieved_at":"2026-06-02T13:59:30.728Z","verification":{"type":"community-validated","markers":["modern-reference checked timing on Narasiṁha Jayantī 2026"],"confidence":"verified"}}],"meta":{"generated_at":"2026-06-02T13:59:30.728Z","pillar_versions":{"Sūrya-Siddhānta":"Pūrṇa","Vidhyamitra-Tier2":"Pūrṇa"}}}