Ruling · Dattātreyotpatti (Datta Jayanti) · 2031

Sunday 28 December

Determinatein Baoding, under the Rashtriya Panchang method. Clear of every threshold by 272 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 Saturday 27 December

Pūrṇimā is absent from pradoṣa. Not taken.

17:02 sunsetpradoṣa ends 18:59
16:3817:0217:2617:5018:1418:3819:0219:26

0 of 116 minutes covered

Evening of Sunday 28 December

Taken. The only evening Pūrṇimā reaches.

17:03 sunsetpradoṣa ends 18:59
16:3917:0317:2717:5118:1518:3919:0319:27

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 23:31 on Sat 27 Dec to 01:33 on Mon 29 Dec.

    2031-12-27T15:30:41Z → 2031-12-28T17:33:02Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 17:02–18:59 on the 27th, 17:03–18:59 on the 28th.

    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 27th and 116 of 116 on the 28th.

    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 16314 s

  5. 05

    Ruling

    Dattātreyotpatti, Baoding, 2031: Sunday 28 December.

    confidence: determinate

Say it like this

In Baoding, Dattātreyotpatti (Datta Jayanti) 2031 falls on Sunday 28 December. Pūrṇimā runs from 23:31 on Sat 27 Dec to 01:33 on Mon 29 Dec and covers all of pradoṣa that evening.

ahargana.org/baoding/festivals/2031/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingSun 28 Dec
Ahargaṇa, classicalDisc centre, no refractionSun 28 Dec
compat-drikpanchangComparison profileSun 28 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 27thCoveredSunset 28thCoveredRuled
Los Angeles07:31 → 09:3316:51113 min16:510 min27 Dec
Chicago09:31 → 11:3316:26119 min16:270 min27 Dec
Jersey City10:31 → 12:3316:35118 min16:360 min27 Dec
Port of Spain11:31 → 13:3317:52100 min17:530 min27 Dec
London15:31 → 17:3315:57129 min15:5896 min27 Dec
Durban17:31 → 19:3318:5880 min18:5934 min27 Dec
Dubai19:31 → 21:3317:370 min17:38107 min28 Dec
Delhi21:01 → 23:0317:310 min17:32109 min28 Dec
Kolkata21:01 → 23:0317:000 min17:01106 min28 Dec
Singapore23:31 → 01:3319:070 min19:0796 min28 Dec
Sydney02:31 → 04:3320:080 min20:0877 min28 Dec
Suva03:31 → 05:3318:430 min18:4486 min28 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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