Ruling · Dattātreyotpatti (Datta Jayanti) · 1908

Monday 7 December

Determinatein Daqing, under the Rashtriya Panchang method. Clear of every threshold by 572 minutes.

Decide it for

DaqingDelhiKolkataSingaporeSydneyJersey City

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 Monday 7 December

Taken. The only evening Pūrṇimā reaches.

15:53 sunsetpradoṣa ends 17:55
15:2915:5316:1716:4117:0517:2917:5318:17

122 of 122 minutes covered

Evening of Tuesday 8 December

Pūrṇimā is absent from pradoṣa. Not taken.

15:52 sunsetpradoṣa ends 17:55
15:2815:5216:1616:4017:0417:2817:5218:16

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 06:21 on Mon 7 Dec to 05:44 on Tue 8 Dec.

    1908-12-06T22:20:50Z → 1908-12-07T21:43:56Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 15:53–17:55 on the 7th, 15:52–17:55 on the 8th.

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

  3. 03

    Rule

    Pūrṇimā must be present during pradoṣa. It covers 122 of 122 minutes on the 7th and 0 of 123 on the 8th.

    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 34303 s

  5. 05

    Ruling

    Dattātreyotpatti, Daqing, 1908: Monday 7 December.

    confidence: determinate

Say it like this

In Daqing, Dattātreyotpatti (Datta Jayanti) 1908 falls on Monday 7 December. Pūrṇimā runs from 06:21 on Mon 7 Dec to 05:44 on Tue 8 Dec and covers all of pradoṣa that evening.

ahargana.org/daqing/festivals/1908/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingMon 7 Dec
Ahargaṇa, classicalDisc centre, no refractionMon 7 Dec
compat-drikpanchangComparison profileMon 7 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 6thCoveredSunset 7thCoveredRuled
Los Angeles14:21 → 13:4416:43112 min16:430 min6 Dec
Chicago16:21 → 15:4416:19117 min16:190 min6 Dec
Jersey City17:21 → 16:4416:2965 min16:2915 min6 Dec
Port of Spain18:21 → 17:4417:4362 min17:431 min6 Dec
London22:21 → 21:4415:520 min15:52128 min7 Dec
Durban00:21 → 23:4418:460 min18:4780 min7 Dec
Dubai02:02 → 01:2517:100 min17:10107 min7 Dec
Delhi03:51 → 03:1417:240 min17:24109 min7 Dec
Kolkata03:51 → 03:1416:520 min16:52106 min7 Dec
Singapore05:21 → 04:4417:570 min17:5796 min7 Dec
Sydney08:21 → 07:4418:550 min18:5678 min7 Dec
Suva10:16 → 09:3918:270 min18:2887 min7 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

About Ahargaṇa