Ruling · Durgā Navamī · 1988

Thursday 17 November

Boundaryin Tehran, under the Rashtriya Panchang method. A threshold is only 3 min 51 s away. Say “contested”.

Decide it for

TehranDelhiKolkataSingaporeSydneyJersey City

35°42′ N 51°25′ E · Asia/Tehran · GeoNames 112931

The two middays

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

Midday of Thursday 17 November

Taken. The only midday Navamī reaches.

madhyāhna begins 11:25  12:13 madhyāhna ends
Navamī begins 12:09:19
10:3711:0111:2511:4912:1312:3713:01

4 of 48 minutes covered, the last 4

Midday of Friday 18 November

Navamī is absent from madhyāhna. Not taken.

madhyāhna begins 11:25  12:13 madhyāhna ends
10:3711:0111:2511:4912:1312:3713:01

0 of 48 minutes covered

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

How it was decided

  1. 01

    Aṅga

    Navamī runs from 12:09 on Thu 17 Nov to 10:06 on Fri 18 Nov.

    1988-11-17T08:39:19Z → 1988-11-18T06:35:33Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:25–12:13 on the 17th, 11:25–12:13 on the 18th.

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

  3. 03

    Rule

    Navamī must be present during madhyāhna. It covers 4 of 48 minutes on the 17th and 0 of 48 on the 18th.

    Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 104

  4. 04

    Tie-break

    Only one midday qualifies. No tie-break is needed.

    priority: purvaviddha → only-day · margin 231 s < 300 s

  5. 05

    Ruling

    Durgā Navamī, Tehran, 1988: Thursday 17 November.

    confidence: boundary (margin)

Say it like this

In Tehran, Durgā Navamī 1988 falls on Thursday 17 November. Navamī runs from 12:09 on Thu 17 Nov to 10:06 on Fri 18 Nov and covers 4 of 48 minutes of madhyāhna that midday. It is 3 min 51 s from a threshold: treat the date as contested.

ahargana.org/tehran/festivals/1988/durga-navami · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingThu 17 Nov
Ahargaṇa, classicalDisc centre, no refractionThu 17 Nov
compat-drikpanchangComparison profileThu 17 Nov
No institution has a recorded ruling for Tehran.

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

The rule, as data

/rules/durga-navami · ruleset 2026.3-draft

Month
Kārtika, amānta
Pakṣa · aṅga
Śukla · Navamī
Kāla
Madhyāhna
Priority
Pūrvaviddhā
Tie-break
First day
Reference
CRC 1955, p. 104

“S 9 Aksaya navami (purvahnavyapini), Jagaddhatri puja (Bengal), (udayavyapini one muhurta), Anla navami (Orissa), Durga navami (purvaviddha), Gauri vrata.” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 104.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlaceNavamīMadhyāhna 17thCoveredMadhyāhna 18thCoveredRuled
Los Angeles00:39 → 22:3611:1448 min11:140 min17 Nov
Chicago02:39 → 00:3611:1148 min11:120 min17 Nov
Jersey City03:39 → 01:3611:1748 min11:170 min17 Nov
Port of Spain04:39 → 02:3611:2748 min11:270 min17 Nov
London08:39 → 06:3611:2148 min11:210 min17 Nov
Durban10:39 → 08:3611:1748 min11:170 min17 Nov
Dubai12:39 → 10:3611:400 min11:400 min18 Nov
Delhi14:09 → 12:0611:420 min11:4223 min18 Nov
Kolkata14:09 → 12:0610:570 min10:5848 min18 Nov
Singapore16:39 → 14:3612:260 min12:2648 min18 Nov
Sydney19:39 → 17:3612:160 min12:1748 min18 Nov
Suva20:39 → 18:3611:270 min11:2848 min18 Nov
Profile · tradition
pac-rp@2026.1 · smarta
Rule
durga-navami@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s

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