Accuracy report 2026

Convention: Navami ran 19 Oct 10:52 to 20 Oct 12:50 IST. DoPT lists the udaya-Navami day (Navami at sunrise, 20 Oct, the same day as Dussehra); the engine applies the tithi-yugma rule (Ashtami-viddha Navami preferred, Nirnaya Sindhu) and gives 19 Oct. DoPT's Mahashtami (19 Oct) matches the engine.

Not explained by the computed ingress, flagged for review: the Makara ingress (calibrated Lahiri) is at 15:13 IST on 14 Jan 2026, before sunset (18:00 at Chennai); the engine's pongal, its Tamil solar-month rule (month from the ingress day when before sunset) and DoPT ('Magha Bihu / Pongal', 14 Jan) all give 14 Jan. G.O.(Ms.) No.708 prints Pongal on 15 Jan (with Thiruvalluvar Day 16 Jan and Uzhavar Thirunal 17 Jan) and states no rule. 2024 (ingress 15 Jan 02:54) and 2025 (14 Jan) agree with the engine.

Convention: Phalguna Purnima ran 2 Mar 17:56 to 3 Mar 17:07 IST, with Bhadra (Vishti) 2 Mar 17:56 to 3 Mar 05:28. At Patna (sunset 17:51 on 2 Mar) only the Pradosh of 2 Mar (17:51-20:19) has Purnima, all of it in Bhadra; on 3 Mar Purnima lasts from sunrise (06:10) to 17:07, more than 3.5 prahars, so the engine's rule for this case (holika_next_day_pradosh_purnima_3_5_prahar) gives Holika Dahan on 3 Mar, as DoPT ('Holika dahan', 3 Mar). The Bihar notification's Schedule-2 #4 keeps Holika Dahan on 2 Mar (printed tithi Phalguna Shukla Chaturdashi/Purnima; its Schedule-3 Holi is 3 Mar, Purnima, and 4 Mar, Pratipada). At Mumbai, where Purnima lasts less than 3.5 prahars on 3 Mar, the engine gives 2 Mar and Maharashtra's 'Holi (Second Day)' 3 Mar matches. 2024 and 2025 agree with the engine.

Convention (as gcal:iskcon-delhi:ram_navami:2026-03-27): Chaitra Shukla Navami ran 26 Mar 11:49 to 27 Mar 10:07 IST. At Patna it covers the Madhyahna of 26 Mar (10:41-13:08) from 11:49 and none of 27 Mar, so the engine's Madhyahna rule gives 26 Mar, as DoPT, Punjab, West Bengal and Maharashtra. The Bihar notification (Schedule-3 #5, printed tithi Chaitra Shukla Navami) lists Ram Navami on 27 Mar, the day Navami prevails at sunrise (05:46). 2024 (17 Apr) and 2025 (6 Apr) agree with the engine.

Not explained by the tithi times, flagged for review: Ashwina Shukla Ashtami ran 18 Oct 08:28 to 19 Oct 10:52 IST, so at Patna (sunrise 05:49) 18 Oct begins in Saptami and 19 Oct has Ashtami at sunrise, joined with Navami from 10:52. The engine's rule gives 19 Oct, as DoPT (Mahashtami, 19 Oct) and West Bengal (Maha Astami, 19 Oct). The Bihar notification (Schedule-3 #17) prints the Durga Puja Ashtami on 18 Oct (Saptami-joined Ashtami), Navami on 19 Oct and Dashami on 20 Oct (both matched) and states no rule. 2024 and 2025 agree with the engine.

Convention (as dopt:2026:maha_navami): Navami ran 19 Oct 10:52 to 20 Oct 12:50 IST; the engine's tithi-yugma rule gives 19 Oct (as Tamil Nadu's Ayutha Pooja, 19 Oct). The Kerala gazette lists Mahanavami on 20 Oct (3 Thulam 1202), the day Navami prevails at sunrise (06:09 at Thiruvananthapuram), like DoPT and West Bengal.

Convention (as dopt:2026:maha_navami): Navami ran 19 Oct 10:52 to 20 Oct 12:50 IST. West Bengal lists Maha Nabami on 20 Oct, the day Navami prevails at sunrise (05:35 at Kolkata); the engine's tithi-yugma rule (Ashtami-joined Navami) gives 19 Oct, the day West Bengal lists Maha Astami (matched) and Bihar its Durga Puja Navami (matched).

Convention (as state:west-bengal-2026:dussehra): Dashami ran 20 Oct 12:50 to 21 Oct 14:12 IST. At Thiruvananthapuram the Aparahna of 20 Oct (13:18-15:41) is wholly in Dashami and that of 21 Oct only until 14:12, so the engine's Aparahna rule (the whole Aparahna on one day before a part on the other; the Vijayadashami Shravana check does not move it) gives 20 Oct (as DoPT, Tamil Nadu, Punjab, Bihar and Maharashtra). The Kerala gazette lists Vijayadasami on 21 Oct (4 Thulam 1202), the day Dashami prevails at sunrise (06:09), like West Bengal's Durga Puja Dasami.

Convention: Dashami ran 20 Oct 12:50 to 21 Oct 14:12 IST; at Kolkata it covers 12:50-14:48 of the 20 Oct Aparahna (118 min) and 12:30-14:12 of the 21 Oct Aparahna (102 min). The parts differ by less than one ghati (24 min) and count as equal (samya), so the engine's Vijayadashami rule takes the first day, 20 Oct (kaal_equal_both_first; as DoPT, Tamil Nadu, Punjab, Bihar and Maharashtra Dasara). West Bengal lists Durga Puja Dasami (Bijoya Dashami, immersion) on 21 Oct, the day Dashami prevails at sunrise (05:35 at Kolkata); the Kerala 2026 gazette's Vijayadasami is also 21 Oct. 2024 and 2025: all agree.

Convention: Kartika Shukla Dwitiya ran 10 Nov 14:00 to 11 Nov 15:53 IST. At Patna the Aparahna of 10 Nov (12:39-14:51) has Dwitiya for 51 min and that of 11 Nov (12:39-14:50) throughout, so the engine's Aparahna rule (greater coverage) gives 11 Nov, as DoPT ('Bhai Duj', 11 Nov), West Bengal (Bhratridwitiya, 11 Nov) and Maharashtra (Bhaubeej, 11 Nov). The Bihar notification (Schedule-1 #11, printed tithi Kartika Shukla Dwitiya) prints 'Chitragupta Puja/ Bhai Dooj' on 10 Nov, the first day with Dwitiya in Aparahna. 2024 (3 Nov) and 2025 (23 Oct) agree with the engine.

Convention: Kartika Shukla Pratipada ran 9 Nov 12:31 to 10 Nov 14:00 IST. At Mumbai it covers more than three muhurtas (136 min) of daylight on both days (9 Nov 12:31-18:01; 10 Nov from sunrise 06:43), so the engine's Govardhan Puja rule takes the first, Amavasya-joined day, 9 Nov (viddha_purva; the Nirnaya Sindhu go-krida rule, as DoPT 2026 and Punjab 2026). Maharashtra's 'Diwali (Bali Pratipada)' is the Balipratipada (Padwa), kept on the day Pratipada prevails at sunrise, 10 Nov; the engine has no separate Bali Pratipada observance (proposed key bali_pratipada). 2024 (2 Nov) and 2025 (22 Oct) agree.

Source misprint. Row 93 prints 17 Mar 2026 in the Gregorian column, but its Saka date, 10 Chaitra 1948, is 31 Mar, a Tuesday, which is the printed weekday. The edition's own daily page for 31 Mar (PDF p. 148, printed 128) lists 'महावीर जयंती (जैन)'. 17 Mar is 26 Phalguna 1947. At the intended date the check passes: rp:rp2526:mahavir_jayanti:2026-03-31:intended matches the engine, and DoPT also has 31 Mar.

Source misprint of row 98, as rp:rp2526:vaisakhi:2026-04-05. The row's intended date is 14 Apr 2026, which the daily page (PDF p. 152) confirms. At that date the check passes: rp:rp2526:mesha_sankranti:2026-04-14:intended matches the engine.

Source misprint of row 98, as rp:rp2526:vaisakhi:2026-04-05. The row's intended date is 14 Apr 2026, which the daily page (PDF p. 152) confirms. At that date the check passes: rp:rp2526:puthandu:2026-04-14:intended matches the engine.

Source misprint. Row 98 repeats row 97's dates (15 Chaitra, (नि) 22 Chaitra, 5 Apr 2026), although it names the nirayana New Year of KY 5127. That New Year is (नि) 1 Vaishakha = 14 Apr 2026, a Tuesday, which is the printed weekday. The daily page for 14 Apr (PDF p. 152, printed 132) lists these festivals, with the Mesha ingress at 09:33 IST. At the intended date the check passes: rp:rp2526:vaisakhi:2026-04-14:intended matches the engine.

Source misprint of row 98, as rp:rp2526:vaisakhi:2026-04-05. The row's intended date is 14 Apr 2026, which the daily page (PDF p. 152) confirms. Vishu also differs from the engine at that date; see rp:rp2526:vishu:2026-04-14:intended.

Convention (Vishu). The Mesha ingress is on 14 Apr 2026 at 09:33 IST by RP (daily page, PDF p. 152) and at 09:39 by the engine, after sunrise. RP lists Vishu on the day of the ingress. The engine keeps Vishu at the first sunrise after the ingress, 15 Apr (Medam 2), as the Government of Kerala notification does (kerala-2026: Vishu 15 Apr 2026).

Convention (Vishu), as rp:rp2526:vishu:2026-04-14:intended. The ingress is on 14 Apr 2026 at 09:33 IST by RP (daily page, PDF p. 26) and at 09:39 by the engine. RP lists Vishu on the day of the ingress. The engine and the Government of Kerala (kerala-2026) have 15 Apr, the first sunrise after the ingress.

Rule difference (Akshaya Tritiya on two days). Vaishakha Shukla Tritiya ran from 19 Apr 10:49 to 20 Apr 07:27 IST. RP's daily pages (PDF pp. 153-154) print Dwitiya ending at 10-50 on 19 Apr and Tritiya ending at 07-28 on 20 Apr, with sunrise at 05:35. RP gives Akshaya Tritiya on 20 Apr, the day on which Tritiya prevails at sunrise (udaya tithi). The engine takes the Purvahna-vyapini Tritiya and, when it touches the forenoon of two days, the Dwitiya-joined first day by the tithi-yugma rule (Nirnaya Sindhu; Garuda Purana 1.128.16-17). That gives 19 Apr, the date of the computed almanacs cited in the rule's source. By forenoon coverage alone, 20 Apr would win (112 against 70 minutes), so the engine's date rests on the yugma rule.

The same date as rp:rp2526:akshaya_tritiya:2026-04-20, printed again in the next edition. Its daily page (PDF p. 28) has Tritiya ending at 07-28 on 20 Apr and lists 'अक्षय्य तृतीया' there. RP uses the udaya tithi; the engine uses the Purvahna rule with the tithi-yugma rule, which gives 19 Apr.

Convention, as dopt:2026:maha_navami. Navami ran from 19 Oct 10:52 to 20 Oct 12:51 IST (RP daily page, PDF p. 75). RP lists Maha Navami on 20 Oct, the day on which Navami prevails at sunrise; the daily page for that day reads 'महानवमी, नवरात्रोत्सवाचे पारणे, विजयादशमी, दसरा'. DoPT, Kerala and West Bengal also have 20 Oct in 2026. The engine's tithi-yugma rule (Navami joined with Ashtami, Nirnaya Sindhu) gives 19 Oct and shows 20 Oct as the udaya alternative. RP's own daily page puts Ayudha Puja, a Navami observance, on 19 Oct, together with Durgashtami.

Vaishnava vs Smarta (as gcal:iskcon-mayapur:ram_navami:2026-03-27): Navami 26 Mar 11:49 to 27 Mar 10:07 IST; at Delhi Navami covers the Madhyahna of 26 Mar from 11:49 to 13:40 and none of 27 Mar (engine 26 Mar, = DoPT); GCal 27 Mar (Navami at sunrise).

Vaishnava vs Smarta: Chaitra Shukla Navami ran 26 Mar 11:49 to 27 Mar 10:07 IST. Only the Madhyahna of 26 Mar has Navami (from 11:49; on 27 Mar it ends at 10:07), so the engine's Madhyahna rule gives 26 Mar (DoPT and West Bengal also 26 Mar). GCal keeps 27 Mar, the day Navami prevails at sunrise (26 Mar begins in Ashtami).

Vaishnava vs Smarta (as gcal:iskcon-mayapur:govardhan_puja:2026-11-10): Pratipada 9 Nov 12:31 to 10 Nov 14:00 IST covers more than three muhurtas (130 min) of daylight at Delhi on both days (9 Nov 12:31-17:30; 10 Nov from sunrise 06:39); engine 9 Nov (Amavasya-joined day, = DoPT), GCal 10 Nov (Pratipada at sunrise).

Vaishnava vs Smarta: Kartika Shukla Pratipada ran 9 Nov 12:31 to 10 Nov 14:00 IST. At Mayapur it covers more than three muhurtas (133 min) of daylight on both days (9 Nov 12:31-16:53; 10 Nov from sunrise 05:47), so the engine's Govardhan Puja rule takes the first, Amavasya-joined day, 9 Nov (viddha_purva, as DoPT 2026). GCal keeps 10 Nov, the day Pratipada prevails at sunrise, the ISKCON day the rule's variation note names. 2024, 2025 and 2027 agree.