Ruling · Dattātreyotpatti (Dattātreya Jayantī) · 2026

Wednesday 23 December

Determinatein Chicago, under the Rashtriya Panchang method. Clear of every threshold by 66 minutes.

Decide it for

ChicagoDelhiKolkataSingaporeSydneyJersey City

41°51′ N 87°39′ W · America/Chicago · GeoNames 4887398

The two evenings

One ghaṭī is 24 minutes. Pradoṣa is 2 muhūrtas after sunset.

Evening of Tuesday 22 December

Pūrṇimā is absent from pradoṣa. Not taken.

16:23 sunsetpradoṣa ends 18:22
15:5916:2316:4717:1117:3517:5918:2318:47

0 of 119 minutes covered

Evening of Wednesday 23 December

Taken. The only evening Pūrṇimā reaches.

16:23 sunsetpradoṣa ends 18:23
15:5916:2316:4717:1117:3517:5918:2318:47

119 of 119 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 23:18 on Tue 22 Dec to 19:28 on Wed 23 Dec.

    2026-12-23T05:17:36Z → 2026-12-24T01:28:14Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 16:23–18:22 on the 22nd, 16:23–18:23 on the 23rd.

    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 119 minutes on the 22nd and 119 of 119 on the 23rd.

    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 3941 s

  5. 05

    Ruling

    Dattātreyotpatti, Chicago, 2026: Wednesday 23 December.

    confidence: determinate

Say it like this

In Chicago, Dattātreyotpatti (Datta Jayanti) 2026 falls on Wednesday 23 December. Pūrṇimā runs from 23:18 on Tue 22 Dec to 19:28 on Wed 23 Dec and covers all of pradoṣa that evening.

ahargana.org/chicago/festivals/2026/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingWed 23 Dec
Ahargaṇa, classicalDisc centre, no refractionWed 23 Dec
compat-drikpanchangComparison profileWed 23 Dec
No institution has a recorded ruling for Chicago.

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 23rdCoveredSunset 24thCoveredRuled
Los Angeles21:18 → 17:2816:4840 min16:490 min23 Dec
Chicago23:18 → 19:2816:23119 min16:240 min23 Dec
Jersey City00:18 → 20:2816:33118 min16:330 min23 Dec
Port of Spain01:18 → 21:2817:50100 min17:510 min23 Dec
London05:18 → 01:2815:54130 min15:550 min23 Dec
Durban07:18 → 03:2818:5780 min18:570 min23 Dec
Dubai09:18 → 05:2817:35107 min17:350 min23 Dec
Delhi10:48 → 06:5817:29110 min17:300 min23 Dec
Kolkata10:48 → 06:5816:58106 min16:580 min23 Dec
Singapore13:18 → 09:2819:0596 min19:050 min23 Dec
Sydney16:18 → 12:2820:0677 min20:070 min23 Dec
Suva17:18 → 13:2818:4286 min18:420 min23 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