Ruling · Guru Pūrṇimā · 2017

Sunday 9 July

Boundaryin Daqing, under the Rashtriya Panchang method. A threshold is only 2 min 25 s away. Say “contested”.

Decide it for

DaqingDelhiKolkataSingaporeSydneyJersey City

46°35′ N 125°00′ E · Asia/Shanghai · GeoNames 2037860

The two middays

One ghaṭī is 24 minutes. Madhyāhna is 1 ghaṭikā either side of midday.

Midday of Saturday 8 July

Qualifies with 48 of 48 minutes. Not taken.

madhyāhna begins 11:21  12:09 madhyāhna ends
10:3310:5711:2111:4512:0912:3312:57

48 of 48 minutes covered

Midday of Sunday 9 July

Taken. Both middays qualify; the rule takes the second.

madhyāhna begins 11:21  12:09 madhyāhna ends
Pūrṇimā ends 12:06:34
10:3310:5711:2111:4512:0912:3312:57

46 of 48 minutes covered, the first 46

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

How it was decided

  1. 01

    Aṅga

    Pūrṇimā runs from 10:01 on Sat 8 Jul to 12:07 on Sun 9 Jul.

    2017-07-08T02:01:27Z → 2017-07-09T04:06:34Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:21–12:09 on the 8th, 11:21–12:09 on the 9th.

    madhyahna: midday-pm-1-ghatika · sunrise and sunset: upper limb, 31′ + 16′

  3. 03

    Rule

    Pūrṇimā must be present during madhyāhna. It covers 48 of 48 minutes on the 8th and 46 of 48 on the 9th.

    Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 102

  4. 04

    Tie-break

    Both middays qualify. Paraviddhā: the second is taken.

    priority: paraviddha → paraviddha · margin 145 s < 300 s

  5. 05

    Ruling

    Guru Pūrṇimā, Daqing, 2017: Sunday 9 July.

    confidence: boundary (margin)

Say it like this

In Daqing, Guru Pūrṇimā 2017 falls on Sunday 9 July. Pūrṇimā runs from 10:01 on Sat 8 Jul to 12:07 on Sun 9 Jul and covers 46 of 48 minutes of madhyāhna that midday. It also reaches the previous midday for 48 minutes; by the rule the second midday is taken. It is 2 min 25 s from a threshold: treat the date as contested.

ahargana.org/daqing/festivals/2017/guru-purnima · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingSun 9 Jul
Ahargaṇa, classicalDisc centre, no refractionSun 9 Jul
compat-drikpanchangComparison profileSun 9 Jul
No institution has a recorded ruling for Daqing.

Institutional rulings are recorded with a source address, and are never edited to agree.

The rule, as data

/rules/guru-purnima · ruleset 2026.3-draft

Month
Āṣāḍha, amānta
Pakṣa · aṅga
Śukla · Pūrṇimā
Kāla
Madhyāhna
Priority
Paraviddhā
Tie-break
Second day
Reference
CRC 1955, p. 102

“S 15 Guru purnima (paraviddha), Vyasa puja (paraviddha, 3 muhurtas after sunrise), Kokila vrata (sayahna vyapini). Siva sayanotsava (pradosavyapini).” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 102.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlacePūrṇimāMadhyāhna 8thCoveredMadhyāhna 9thCoveredRuled
Los Angeles19:01 → 21:0712:3448 min12:340 min8 Jul
Chicago21:01 → 23:0712:3248 min12:320 min8 Jul
Jersey City22:01 → 00:0712:3748 min12:370 min8 Jul
Port of Spain22:01 → 00:0711:4748 min11:470 min8 Jul
London03:01 → 05:0712:4148 min12:410 min8 Jul
Durban04:01 → 06:0711:3748 min11:370 min8 Jul
Dubai06:01 → 08:0712:0048 min12:000 min8 Jul
Delhi07:31 → 09:3712:0248 min12:020 min8 Jul
Kolkata07:31 → 09:3711:1848 min11:180 min8 Jul
Singapore10:01 → 12:0712:4648 min12:460 min8 Jul
Sydney12:01 → 14:0711:3623 min11:3648 min9 Jul
Suva14:01 → 16:0711:470 min11:4848 min9 Jul
Profile · tradition
pac-rp@2026.1 · smarta
Rule
guru-purnima@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s

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