Ruling · Dattātreyotpatti (Dattātreya Jayantī) · 1978

Thursday 14 December

Determinatein Baoding, under the Rashtriya Panchang method. Clear of every threshold by 23 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 Wednesday 13 December

Pūrṇimā is absent from pradoṣa. Not taken.

16:56 sunsetpradoṣa ends 18:53
Pūrṇimā begins 19:15:42
16:3216:5617:2017:4418:0818:3218:5619:20

0 of 116 minutes covered

Evening of Thursday 14 December

Taken. The only evening Pūrṇimā reaches.

16:56 sunsetpradoṣa ends 18:53
16:3216:5617:2017:4418:0818:3218:5619:20

116 of 116 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 19:16 on Wed 13 Dec to 20:31 on Thu 14 Dec.

    1978-12-13T11:15:43Z → 1978-12-14T12:30:39Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 16:56–18:53 on the 13th, 16:56–18:53 on the 14th.

    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 13th and 116 of 116 on the 14th.

    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 1390 s

  5. 05

    Ruling

    Dattātreyotpatti, Baoding, 1978: Thursday 14 December.

    confidence: determinate

Say it like this

In Baoding, Dattātreyotpatti (Datta Jayanti) 1978 falls on Thursday 14 December. Pūrṇimā runs from 19:16 on Wed 13 Dec to 20:31 on Thu 14 Dec and covers all of pradoṣa that evening.

ahargana.org/baoding/festivals/1978/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingThu 14 Dec
Ahargaṇa, classicalDisc centre, no refractionThu 14 Dec
compat-drikpanchangComparison profileThu 14 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 13thCoveredSunset 14thCoveredRuled
Los Angeles03:16 → 04:3116:44113 min16:450 min13 Dec
Chicago05:16 → 06:3116:20119 min16:200 min13 Dec
Jersey City06:16 → 07:3116:29118 min16:290 min13 Dec
Port of Spain07:16 → 08:3117:45100 min17:460 min13 Dec
London11:16 → 12:3115:51129 min15:510 min13 Dec
Durban13:16 → 14:3118:5180 min18:520 min13 Dec
Dubai15:16 → 16:3117:31107 min17:310 min13 Dec
Delhi16:46 → 18:0117:25109 min17:2535 min13 Dec
Kolkata16:46 → 18:0116:53106 min16:5467 min13 Dec
Singapore18:46 → 20:0118:3080 min18:3090 min14 Dec
Sydney22:16 → 23:3120:000 min20:0177 min14 Dec
Suva23:16 → 00:3118:360 min18:3786 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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