Ruling · Dattātreyotpatti (Datta Jayanti) · 1929

Monday 16 December

Determinatein Baoding, under the Rashtriya Panchang method. Clear of every threshold by 45 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 Sunday 15 December

Pūrṇimā is absent from pradoṣa. Not taken.

16:57 sunsetpradoṣa ends 18:53
16:3316:5717:2117:4518:0918:3318:5719:21

0 of 116 minutes covered

Evening of Monday 16 December

Taken. The only evening Pūrṇimā reaches.

16:57 sunsetpradoṣa ends 18:54
16:3316:5717:2117:4518:0918:3318:5719:21

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 23:01 on Sun 15 Dec to 19:38 on Mon 16 Dec.

    1929-12-15T15:01:06Z → 1929-12-16T11:38:08Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 16:57–18:53 on the 15th, 16:57–18:54 on the 16th.

    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 15th and 116 of 116 on the 16th.

    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 2678 s

  5. 05

    Ruling

    Dattātreyotpatti, Baoding, 1929: Monday 16 December.

    confidence: determinate

Say it like this

In Baoding, Dattātreyotpatti (Datta Jayanti) 1929 falls on Monday 16 December. Pūrṇimā runs from 23:01 on Sun 15 Dec to 19:38 on Mon 16 Dec and covers all of pradoṣa that evening.

ahargana.org/baoding/festivals/1929/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingMon 16 Dec
Ahargaṇa, classicalDisc centre, no refractionMon 16 Dec
compat-drikpanchangComparison profileMon 16 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 15thCoveredSunset 16thCoveredRuled
Los Angeles07:01 → 03:3816:45113 min16:450 min15 Dec
Chicago09:01 → 05:3816:20119 min16:200 min15 Dec
Jersey City10:01 → 06:3816:29118 min16:300 min15 Dec
Port of Spain11:01 → 07:3817:46100 min17:470 min15 Dec
London15:01 → 11:3815:51129 min15:510 min15 Dec
Durban17:01 → 13:3818:5280 min18:530 min15 Dec
Dubai19:01 → 15:3817:3118 min17:320 min15 Dec
Delhi20:31 → 17:0817:260 min17:260 min15 Dec
Kolkata20:31 → 17:0816:540 min16:5514 min16 Dec
Singapore22:01 → 18:3818:010 min18:0137 min16 Dec
Sydney01:01 → 21:3819:020 min19:0277 min16 Dec
Suva03:01 → 23:3818:370 min18:3886 min16 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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