Accuracy report 2024

Convention, not a rule error (for the Jyotish reviewer): the Makara ingress was at 02:54 IST on 15 Jan 2024, after midnight and before that day's sunrise (07:15 at New Delhi), i.e. inside the Hindu (sunrise-to-sunrise) day that began on 14 Jan. DoPT prints 'Makar Sankranti' on the same civil date, 14 Jan, in every OM 2024-2027, a date that in each of those years is also the Hindu day containing the ingress; it prints 'Magha Bihu/ Pongal' on 15 Jan (Annexure II #4), which the engine's pongal matches. The engine's day is the classical Makara Punya Kaal (Dharma Sindhu, Sankranti-nirnaya: a Makara ingress at night, before or after midnight, has its Punya Kaal on the following day from sunrise; rule sankranti_makara_night_next_day): 15 Jan. The Bihar Government's 2024 notification (Schedule-2 #2, printed tithi Pausha Shukla Chaturthi) keeps Makar Sankranti on 15 Jan, as the engine does at Patna, and the Government of India almanac gives the engine's day after the night ingress of 2027 (see dopt:2027:makar_sankranti). The engine's Lohri (the eve of 1 Magh, the Hindu day of the ingress) is 13 Jan 2024, as DoPT.

Convention: Amavasya ran 31 Oct 15:53 to 1 Nov 18:17 IST, and New Delhi sunset was 17:36 / 17:35, so Amavasya touches the Pradosh of both evenings, for 42 min on 1 Nov. The engine takes the second evening when that overlap is at least 24 min (one ghati) and gives 1 Nov. DoPT keeps 31 Oct, the evening whose whole Pradosh and Nishita fall in Amavasya, as do Punjab (Chandigarh, 43 min on 1 Nov) and Bihar (Patna, 69 min). At Mumbai the overlap was 13 min and the engine gives 31 Oct, where the Maharashtra gazette has 1 Nov.

Convention: Vaishakha Shukla Navami ran 16 May 06:23 to 17 May 08:49 IST; at Patna (sunrise 05:03) the Madhyahna of 16 May (10:25-13:06) is in Navami, so the engine's Madhyahna rule gives 16 May. The Bihar notification (Schedule-1 #9, printed tithi Vaishakha Shukla Navami) keeps Janaki Navami on 17 May, the day Navami prevails at sunrise (udaya). 2026 (Navami 24 Apr 19:22 to 25 Apr 18:28): both 25 Apr.

Convention: Ashwina Shukla Navami ran 11 Oct 12:07 to 12 Oct 10:58 IST. The engine's tithi-yugma rule (the Ashtami-joined Navami, Nirnaya Sindhu) gives 11 Oct, as do DoPT ('Dussehra (Mahashtami) /Dussehra (Mahanavmi)', 11 Oct), Tamil Nadu (Ayutha Pooja, 11 Oct) and West Bengal (Maha Astami and Maha Nabami, 11 Oct). The Kerala gazette lists Mahanavami on 12 Oct (26 Kanni 1200), the day Navami prevails at sunrise (06:09 at Thiruvananthapuram). Kerala 2025 (1 Oct) agrees with the engine.

Convention: Dashami ran 12 Oct 10:58 to 13 Oct 09:09 IST. At Thiruvananthapuram only the Aparahna of 12 Oct (13:20-15:43) has Dashami, so the engine's Aparahna rule gives 12 Oct (the Vijayadashami Shravana check keeps it: Shravana is not at the 13 Oct Aparahna), as do DoPT (Dussehra), Tamil Nadu (Vijaya Dasami) and West Bengal (Dasami). The Kerala gazette lists Vijayadasami on 13 Oct (27 Kanni 1200), the day Dashami prevails at sunrise (06:09). Kerala 2025 (2 Oct) agrees with the engine.

Convention (as dopt:2024:diwali): Amavasya ran 31 Oct 15:53 to 1 Nov 18:17 IST; at Patna (sunset 17:08 on 1 Nov) it touches the Pradosh of both evenings, 69 min on 1 Nov, so the engine's rule (second evening when the overlap is at least 24 min) gives 1 Nov. The Bihar notification (Schedule-3 #15, printed tithi Kartika Krishna Amavasya) keeps Deepavali on 31 Oct, the evening whose whole Pradosh and Nishita fall in Amavasya, as DoPT and Punjab.

Convention (as dopt:2024:diwali): Amavasya ran 31 Oct 15:53 to 1 Nov 18:17 IST; at Chandigarh (sunset 17:35 / 17:34) it touches the Pradosh of both evenings, 43 min on 1 Nov, so the engine's rule (second evening when the overlap is at least one ghati, 24 min) gives 1 Nov. The Punjab notification (Schedule #25) keeps Diwali on 31 Oct, the evening whose whole Pradosh and Nishita fall in Amavasya. 2021-2023, 2025 and 2026 agree with the engine.

Convention: Amavasya ran 31 Oct 15:53 to 1 Nov 18:17 IST; at Mumbai (sunset 18:05 / 18:04) it touches the Pradosh of both evenings, only 13 min on 1 Nov, below the engine's 24-min minimum for the second evening, so the engine gives 31 Oct. The Maharashtra gazette keeps Diwali Amavasya (Laxmi Pujan) on 1 Nov. (At New Delhi the overlap is 42 min: engine 1 Nov, DoPT 31 Oct.)

Convention (Vishu). The Mesha ingress was on 13 Apr 2024 at 21:04 IST by RP (daily page, PDF p. 28) and at 21:15 by the engine. RP lists Vishu (Kerala) on the Hindu day that contains the ingress, together with Vaisakhi and Mesha Sankranti (Odisha), which both match the engine on 13 Apr. The engine keeps Vishu at the first sunrise after the ingress, when the Vishukkani is seen, which gives 14 Apr. That is also the date in the Government of Kerala list (holidays-in.json, kerala-2024).

Rule difference (Diwali when two evenings have Amavasya in Pradosh). Amavasya ran from 31 Oct 15:53 to 1 Nov 18:17 IST. RP's daily page (PDF p. 94) prints the same ending times and a sunset of 17:21 on 1 Nov, so Amavasya covers the Pradosh of both evenings, 56 min of it on 1 Nov at the central station. The engine takes the second evening when that overlap is at least one ghati (24 min), which gives 1 Nov. RP keeps Lakshmi Puja, Kali Puja and Deepavali on 31 Oct, the evening whose whole Pradosh and night are in Amavasya. DoPT does the same (dopt:2024:diwali).

Vaishnava vs Smarta: Vaishakha Shukla Chaturdashi ran 21 May 17:40 to 22 May 18:48 IST; at Delhi (sunset 19:08 / 19:09) only the evening of 21 May has Chaturdashi in Pradosh, so the engine's Pradosh rule gives 21 May. GCal keeps 22 May, the day Chaturdashi prevails at sunrise. At Mayapur (sunset 18:14) both evenings have it and the engine's tithi-yugma rule gives 22 May = GCal.