Ruling · Guru Pūrṇimā · 1981

Friday 17 July

Determinatein Daqing, under the Rashtriya Panchang method. Clear of every threshold by 24 minutes.

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 Thursday 16 July

Qualifies with 24 of 48 minutes. Not taken.

madhyāhna begins 11:22  12:10 madhyāhna ends
Pūrṇimā begins 11:45:32
10:3410:5811:2211:4612:1012:3412:58

24 of 48 minutes covered, the last 24

Midday of Friday 17 July

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

madhyāhna begins 11:22  12:10 madhyāhna ends
Pūrṇimā ends 12:38:49
10:3410:5811:2211:4612:1012:3412:58

48 of 48 minutes covered

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

How it was decided

  1. 01

    Aṅga

    Pūrṇimā runs from 11:46 on Thu 16 Jul to 12:39 on Fri 17 Jul.

    1981-07-16T03:45:33Z → 1981-07-17T04:38:49Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:22–12:10 on the 16th, 11:22–12:10 on the 17th.

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

  3. 03

    Rule

    Pūrṇimā must be present during madhyāhna. It covers 24 of 48 minutes on the 16th and 48 of 48 on the 17th.

    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 1434 s

  5. 05

    Ruling

    Guru Pūrṇimā, Daqing, 1981: Friday 17 July.

    confidence: determinate

Say it like this

In Daqing, Guru Pūrṇimā 1981 falls on Friday 17 July. Pūrṇimā runs from 11:46 on Thu 16 Jul to 12:39 on Fri 17 Jul and covers all of madhyāhna that midday. It also reaches the previous midday for 24 minutes; by the rule the second midday is taken.

ahargana.org/daqing/festivals/1981/guru-purnima · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingFri 17 Jul
Ahargaṇa, classicalDisc centre, no refractionFri 17 Jul
compat-drikpanchangComparison profileFri 17 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 16thCoveredMadhyāhna 17thCoveredRuled
Los Angeles20:46 → 21:3912:3548 min12:350 min16 Jul
Chicago22:46 → 23:3912:3248 min12:320 min16 Jul
Jersey City23:46 → 00:3912:3848 min12:380 min16 Jul
Port of Spain23:46 → 00:3911:4848 min11:480 min16 Jul
London04:46 → 05:3912:4248 min12:420 min16 Jul
Durban05:46 → 06:3911:3848 min11:380 min16 Jul
Dubai07:46 → 08:3912:0148 min12:010 min16 Jul
Delhi09:16 → 10:0912:0348 min12:030 min16 Jul
Kolkata09:16 → 10:0911:1848 min11:180 min16 Jul
Singapore11:16 → 12:0912:1748 min12:170 min16 Jul
Sydney13:46 → 14:3911:370 min11:3748 min17 Jul
Suva15:46 → 16:3911:480 min11:4848 min17 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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