Ruling · Dattātreyotpatti (Datta Jayanti) · 1975

Thursday 18 December

Determinatein Baoding, under the Rashtriya Panchang method. Clear of every threshold by 225 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 17 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 117 minutes covered

Evening of Thursday 18 December

Taken. The only evening Pūrṇimā reaches.

16:58 sunsetpradoṣa ends 18:54
16:3416:5817:2217:4618:1018:3418:5819:22

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 22:44 on Wed 17 Dec to 22:39 on Thu 18 Dec.

    1975-12-17T14:43:55Z → 1975-12-18T14:39:28Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 16:57–18:54 on the 17th, 16:58–18:54 on the 18th.

    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 117 minutes on the 17th and 117 of 117 on the 18th.

    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 13521 s

  5. 05

    Ruling

    Dattātreyotpatti, Baoding, 1975: Thursday 18 December.

    confidence: determinate

Say it like this

In Baoding, Dattātreyotpatti (Datta Jayanti) 1975 falls on Thursday 18 December. Pūrṇimā runs from 22:44 on Wed 17 Dec to 22:39 on Thu 18 Dec and covers all of pradoṣa that evening.

ahargana.org/baoding/festivals/1975/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingThu 18 Dec
Ahargaṇa, classicalDisc centre, no refractionThu 18 Dec
compat-drikpanchangComparison profileThu 18 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 17thCoveredSunset 18thCoveredRuled
Los Angeles06:44 → 06:3916:46113 min16:460 min17 Dec
Chicago08:44 → 08:3916:21119 min16:210 min17 Dec
Jersey City09:44 → 09:3916:30118 min16:300 min17 Dec
Port of Spain10:44 → 10:3917:47100 min17:470 min17 Dec
London14:44 → 14:3915:51129 min15:520 min17 Dec
Durban16:44 → 16:3918:5380 min18:540 min17 Dec
Dubai18:44 → 18:3917:3235 min17:3267 min18 Dec
Delhi20:14 → 20:0917:260 min17:27110 min18 Dec
Kolkata20:14 → 20:0916:550 min16:55106 min18 Dec
Singapore22:14 → 22:0918:320 min18:3296 min18 Dec
Sydney01:44 → 01:3920:030 min20:0377 min18 Dec
Suva02:44 → 02:3918:380 min18:3986 min18 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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