Ruling · Mahānavamī · 2013

Sunday 13 October

Determinatein Tehran, under the Rashtriya Panchang method. Clear of every threshold by 8 min 16 s.

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 Saturday 12 October

Navamī is absent from madhyāhna. Not taken.

madhyāhna begins 11:27  12:15 madhyāhna ends
10:3911:0311:2711:5112:1512:3913:03

0 of 48 minutes covered

Midday of Sunday 13 October

Taken. Navamī reaches neither midday; the rule takes the second day.

madhyāhna begins 11:26  12:14 madhyāhna ends
Navamī ends 11:18:00
10:3811:0211:2611:5012:1412:3813:02

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 13:27 on Sat 12 Oct to 11:18 on Sun 13 Oct.

    2013-10-12T09:56:35Z → 2013-10-13T07:48:01Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:27–12:15 on the 12th, 11:26–12:14 on the 13th.

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

  3. 03

    Rule

    Navamī must be present during madhyāhna. It covers 0 of 48 minutes on the 12th and 0 of 48 on the 13th.

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

  4. 04

    Tie-break

    Neither midday qualifies. The rule takes the second day.

    priority: purvaviddha → second-day · margin 496 s

  5. 05

    Ruling

    Mahānavamī, Tehran, 2013: Sunday 13 October.

    confidence: determinate

Say it like this

In Tehran, Mahānavamī 2013 falls on Sunday 13 October. Navamī runs from 13:27 on Sat 12 Oct to 11:18 on Sun 13 Oct, and reaches madhyāhna on neither day.

ahargana.org/tehran/festivals/2013/mahanavami · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingSun 13 Oct
Ahargaṇa, classicalDisc centre, no refractionSun 13 Oct
compat-drikpanchangComparison profileSun 13 Oct
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/mahanavami · ruleset 2026.3-draft

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

“S 9 Mahanavami (purvaviddha) (In Bengal it is observed as paraviddha covering one muhurta from sunrise).” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 104. The Bengal reading (paraviddha, one muhūrta from sunrise) is not applied.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlaceNavamīMadhyāhna 12thCoveredMadhyāhna 13thCoveredRuled
Los Angeles02:57 → 00:4812:1548 min12:150 min12 Oct
Chicago04:57 → 02:4812:1348 min12:120 min12 Oct
Jersey City05:57 → 03:4812:1848 min12:180 min12 Oct
Port of Spain05:57 → 03:4811:2848 min11:280 min12 Oct
London10:57 → 08:4812:2348 min12:220 min12 Oct
Durban11:57 → 09:4811:1910 min11:180 min12 Oct
Dubai13:57 → 11:4811:410 min11:417 min13 Oct
Delhi15:27 → 13:1811:430 min11:4348 min13 Oct
Kolkata15:27 → 13:1810:590 min10:5948 min13 Oct
Singapore17:57 → 15:4812:270 min12:2748 min13 Oct
Sydney20:57 → 18:4812:180 min12:1848 min13 Oct
Suva21:57 → 19:4811:290 min11:2948 min13 Oct
Profile · tradition
pac-rp@2026.1 · smarta
Rule
mahanavami@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s

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