Ruling · Dattātreyotpatti (Datta Jayanti) · 1921

Wednesday 14 December

Determinatein Daqing, under the Rashtriya Panchang method. Clear of every threshold by 179 minutes.

Decide it for

46°35′ N 125°00′ E · Asia/Shanghai · GeoNames 2037860

The two evenings

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

Evening of Wednesday 14 December

Taken. The only evening Pūrṇimā reaches.

15:52 sunsetpradoṣa ends 17:56
15:2815:5216:1616:4017:0417:2817:5218:16

123 of 123 minutes covered

Evening of Thursday 15 December

Pūrṇimā is absent from pradoṣa. Not taken.

15:53 sunsetpradoṣa ends 17:56
15:2915:5316:1716:4117:0517:2917:5318:17

0 of 123 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 12:54 on Wed 14 Dec to 10:50 on Thu 15 Dec.

    1921-12-14T04:53:40Z → 1921-12-15T02:50:14Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 15:52–17:56 on the 14th, 15:53–17:56 on the 15th.

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

  3. 03

    Rule

    Pūrṇimā must be present during pradoṣa. It covers 123 of 123 minutes on the 14th and 0 of 123 on the 15th.

    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 10721 s

  5. 05

    Ruling

    Dattātreyotpatti, Daqing, 1921: Wednesday 14 December.

    confidence: determinate

Say it like this

In Daqing, Dattātreyotpatti (Datta Jayanti) 1921 falls on Wednesday 14 December. Pūrṇimā runs from 12:54 on Wed 14 Dec to 10:50 on Thu 15 Dec and covers all of pradoṣa that evening.

ahargana.org/daqing/festivals/1921/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingWed 14 Dec
Ahargaṇa, classicalDisc centre, no refractionWed 14 Dec
compat-drikpanchangComparison profileWed 14 Dec
No institution has a recorded ruling for Daqing.

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 14thCoveredSunset 15thCoveredRuled
Los Angeles20:54 → 18:5016:45113 min16:450 min14 Dec
Chicago22:54 → 20:5016:20119 min16:200 min14 Dec
Jersey City23:54 → 21:5016:29118 min16:290 min14 Dec
Port of Spain00:54 → 22:5017:46100 min17:460 min14 Dec
London04:54 → 02:5015:51129 min15:510 min14 Dec
Durban06:54 → 04:5018:5280 min18:520 min14 Dec
Dubai08:54 → 06:5017:31107 min17:310 min14 Dec
Delhi10:24 → 08:2017:25109 min17:260 min14 Dec
Kolkata10:24 → 08:2016:54106 min16:540 min14 Dec
Singapore11:54 → 09:5018:0096 min18:010 min14 Dec
Sydney14:54 → 12:5019:0177 min19:020 min14 Dec
Suva16:54 → 14:5018:3786 min18:370 min14 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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