Ruling · Dattātreyotpatti (Datta Jayanti) · 2010

Monday 20 December

Determinatein Baoding, under the Rashtriya Panchang method. Clear of every threshold by 20 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 Monday 20 December

Taken. The only evening Pūrṇimā reaches.

16:58 sunsetpradoṣa ends 18:55
Pūrṇimā begins 17:18:08
16:3416:5817:2217:4618:1018:3418:5819:22

97 of 117 minutes covered, the last 97

Evening of Tuesday 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

Pūrṇimā presentPradoṣa, the window the rule readsThe instant the tithi begins or ends

How it was decided

  1. 01

    Aṅga

    Pūrṇimā runs from 17:18 on Mon 20 Dec to 16:13 on Tue 21 Dec.

    2010-12-20T09:18:08Z → 2010-12-21T08:13:27Z

  2. 02

    Kāla

    Pradoṣa is 2 muhūrtas after sunset: 16:58–18:55 on the 20th, 16:59–18:56 on the 21st.

    pradosha: night-muhurta-1-2 · sunrise and sunset: upper limb, 31′ + 16′

  3. 03

    Rule

    Pūrṇimā must be present during pradoṣa. It covers 97 of 117 minutes on the 20th and 0 of 117 on the 21st.

    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 1178 s

  5. 05

    Ruling

    Dattātreyotpatti, Baoding, 2010: Monday 20 December.

    confidence: determinate

Say it like this

In Baoding, Dattātreyotpatti (Datta Jayanti) 2010 falls on Monday 20 December. Pūrṇimā runs from 17:18 on Mon 20 Dec to 16:13 on Tue 21 Dec and covers 97 of 117 minutes of pradoṣa that evening.

ahargana.org/baoding/festivals/2010/dattatreyotpatti · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingMon 20 Dec
Ahargaṇa, classicalDisc centre, no refractionMon 20 Dec
compat-drikpanchangComparison profileMon 20 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 20thCoveredSunset 21stCoveredRuled
Los Angeles01:18 → 00:1316:47113 min16:470 min20 Dec
Chicago03:18 → 02:1316:22119 min16:220 min20 Dec
Jersey City04:18 → 03:1316:31118 min16:320 min20 Dec
Port of Spain05:18 → 04:1317:49100 min17:490 min20 Dec
London09:18 → 08:1315:52130 min15:530 min20 Dec
Durban11:18 → 10:1318:5580 min18:560 min20 Dec
Dubai13:18 → 12:1317:33107 min17:340 min20 Dec
Delhi14:48 → 13:4317:28110 min17:280 min20 Dec
Kolkata14:48 → 13:4316:56106 min16:570 min20 Dec
Singapore17:18 → 16:1319:0396 min19:040 min20 Dec
Sydney20:18 → 19:1320:0563 min20:050 min20 Dec
Suva22:18 → 21:1319:400 min19:4086 min21 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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