Ruling · Dattātreyotpatti (Dattātreya Jayantī) · 2018

Saturday 22 December

Determinatein Baoding, under the Rashtriya Panchang method. Clear of every threshold by 412 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 Friday 21 December

Pūrṇimā is absent from pradoṣa. Not taken.

16:59 sunsetpradoṣa ends 18:56
16:3516:5917:2317:4718:1118:3518:5919:23

0 of 117 minutes covered

Evening of Saturday 22 December

Taken. The only evening Pūrṇimā reaches.

16:59 sunsetpradoṣa ends 18:56
16:3516:5917:2317:4718:1118:3518:5919:23

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 04:39 on Sat 22 Dec to 01:49 on Sun 23 Dec.

    2018-12-21T20:39:22Z → 2018-12-22T17:48:35Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 16:59–18:56 on the 21st, 16:59–18:56 on the 22nd.

    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 21st and 117 of 117 on the 22nd.

    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 24749 s

  5. 05

    Ruling

    Dattātreyotpatti, Baoding, 2018: Saturday 22 December.

    confidence: determinate

Say it like this

In Baoding, Dattātreyotpatti (Datta Jayanti) 2018 falls on Saturday 22 December. Pūrṇimā runs from 04:39 on Sat 22 Dec to 01:49 on Sun 23 Dec and covers all of pradoṣa that evening.

ahargana.org/baoding/festivals/2018/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingSat 22 Dec
Ahargaṇa, classicalDisc centre, no refractionSat 22 Dec
compat-drikpanchangComparison profileSat 22 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 21stCoveredSunset 22ndCoveredRuled
Los Angeles12:39 → 09:4916:47113 min16:480 min21 Dec
Chicago14:39 → 11:4916:22119 min16:230 min21 Dec
Jersey City15:39 → 12:4916:32118 min16:320 min21 Dec
Port of Spain16:39 → 13:4917:49100 min17:500 min21 Dec
London20:39 → 17:4915:530 min15:53115 min22 Dec
Durban22:39 → 19:4918:560 min18:5652 min22 Dec
Dubai00:39 → 21:4917:340 min17:34107 min22 Dec
Delhi02:09 → 23:1917:280 min17:29110 min22 Dec
Kolkata02:09 → 23:1916:570 min16:57106 min22 Dec
Singapore04:39 → 01:4919:040 min19:0496 min22 Dec
Sydney07:39 → 04:4920:050 min20:0677 min22 Dec
Suva09:39 → 06:4919:410 min19:4186 min22 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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