Ruling · Dattātreyotpatti (Datta Jayanti) · 1937

Friday 17 December

Determinatein Baoding, under the Rashtriya Panchang method. Clear of every threshold by 479 minutes.

Decide it for

BaodingDelhiKolkataSingaporeSydneyJersey City

38°52′ N 115°28′ E · Asia/Shanghai · GeoNames 1816971

The two evenings

One ghaṭī is 24 minutes. Pradoṣa is 2 muhūrtas after sunset.

Evening of Thursday 16 December

Pūrṇimā is absent from pradoṣa. Not taken.

16:57 sunsetpradoṣa ends 18:54
16:3316:5717:2117:4518:0918:3318:5719:21

0 of 116 minutes covered

Evening of Friday 17 December

Taken. The only evening Pūrṇimā reaches.

16:57 sunsetpradoṣa ends 18:54
16:3316:5717:2117:4518:0918:3318:5719:21

117 of 117 minutes covered

Pūrṇimā presentPradoṣa, the window the rule readsThe instant the tithi begins or ends

How it was decided

  1. 01

    Aṅga

    Pūrṇimā runs from 06:38 on Fri 17 Dec to 02:52 on Sat 18 Dec.

    1937-12-16T22:38:24Z → 1937-12-17T18:52:24Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 16:57–18:54 on the 16th, 16:57–18:54 on the 17th.

    pradosha: night-muhurta-1-2 · sunrise and sunset: upper limb, 31′ + 16′

  3. 03

    Rule

    Pūrṇimā must be present during pradoṣa. It covers 0 of 116 minutes on the 16th and 117 of 117 on the 17th.

    Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 104

  4. 04

    Tie-break

    Only one evening qualifies. No tie-break is needed.

    priority: unstated → only-day · margin 28711 s

  5. 05

    Ruling

    Dattātreyotpatti, Baoding, 1937: Friday 17 December.

    confidence: determinate

Say it like this

In Baoding, Dattātreyotpatti (Datta Jayanti) 1937 falls on Friday 17 December. Pūrṇimā runs from 06:38 on Fri 17 Dec to 02:52 on Sat 18 Dec and covers all of pradoṣa that evening.

ahargana.org/baoding/festivals/1937/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingFri 17 Dec
Ahargaṇa, classicalDisc centre, no refractionFri 17 Dec
compat-drikpanchangComparison profileFri 17 Dec
No institution has a recorded ruling for Baoding.

Institutional rulings are recorded with a source address, and are never edited to agree.

The rule, as data

/rules/dattatreyotpatti · ruleset 2026.3-draft

Month
Mārgaśīrṣa, amānta
Pakṣa · aṅga
Śukla · Pūrṇimā
Kāla
Pradoṣa
Priority
Unstated
Tie-break
Longer coverage, as a boundary
Reference
CRC 1955, p. 104

“S 15 Dattatreyotpatti (pradosa).” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 104.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlacePūrṇimāSunset 16thCoveredSunset 17thCoveredRuled
Los Angeles14:38 → 10:5216:45113 min16:460 min16 Dec
Chicago16:38 → 12:5216:20101 min16:210 min16 Dec
Jersey City17:38 → 13:5216:3049 min16:300 min16 Dec
Port of Spain18:38 → 14:5217:4748 min17:470 min16 Dec
London22:38 → 18:5215:510 min15:51129 min17 Dec
Durban00:38 → 20:5218:530 min18:5480 min17 Dec
Dubai02:38 → 22:5217:320 min17:32107 min17 Dec
Delhi04:08 → 00:2217:260 min17:27110 min17 Dec
Kolkata04:08 → 00:2216:550 min16:55106 min17 Dec
Singapore05:58 → 02:1218:210 min18:2296 min17 Dec
Sydney08:38 → 04:5219:020 min19:0377 min17 Dec
Suva10:38 → 06:5218:380 min18:3886 min17 Dec
Profile · tradition
pac-rp@2026.1 · smarta
Rule
dattatreyotpatti@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s

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