Ruling · Mahānavamī · 2005

Tuesday 11 October

Boundaryin Chattogram, under the Rashtriya Panchang method. A threshold is only 4 min 04 s away. Say “contested”.

Decide it for

ChattogramDelhiKolkataSingaporeSydneyJersey City

22°20′ N 91°50′ E · Asia/Dhaka · GeoNames 1205733

The two middays

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

Midday of Tuesday 11 October

Taken. The only midday Navamī reaches.

madhyāhna begins 11:15  12:03 madhyāhna ends
Navamī begins 11:59:14
10:2710:5111:1511:3912:0312:2712:51

4 of 48 minutes covered, the last 4

Midday of Wednesday 12 October

Navamī is absent from madhyāhna. Not taken.

madhyāhna begins 11:15  12:03 madhyāhna ends
10:2710:5111:1511:3912:0312:2712:51

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 11:59 on Tue 11 Oct to 09:43 on Wed 12 Oct.

    2005-10-11T05:59:14Z → 2005-10-12T03:42:50Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:15–12:03 on the 11th, 11:15–12:03 on the 12th.

    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 11th and 0 of 48 on the 12th.

    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 244 s < 300 s

  5. 05

    Ruling

    Mahānavamī, Chattogram, 2005: Tuesday 11 October.

    confidence: boundary (margin)

Say it like this

In Chattogram, Mahānavamī 2005 falls on Tuesday 11 October. Navamī runs from 11:59 on Tue 11 Oct to 09:43 on Wed 12 Oct and covers 4 of 48 minutes of madhyāhna that midday. It is 4 min 04 s from a threshold: treat the date as contested.

ahargana.org/chattogram/festivals/2005/mahanavami · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingTue 11 Oct
Ahargaṇa, classicalDisc centre, no refractionTue 11 Oct
compat-drikpanchangComparison profileTue 11 Oct
No institution has a recorded ruling for Chattogram.

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 11thCoveredMadhyāhna 12thCoveredRuled
Los Angeles22:59 → 20:4312:1548 min12:150 min11 Oct
Chicago00:59 → 22:4312:1348 min12:130 min11 Oct
Jersey City01:59 → 23:4312:1948 min12:180 min11 Oct
Port of Spain01:59 → 23:4311:2948 min11:280 min11 Oct
London06:59 → 04:4312:2348 min12:230 min11 Oct
Durban07:59 → 05:4311:1948 min11:190 min11 Oct
Dubai09:59 → 07:4311:4148 min11:410 min11 Oct
Delhi11:29 → 09:1311:4448 min11:430 min11 Oct
Kolkata11:29 → 09:1310:5918 min10:590 min11 Oct
Singapore13:59 → 11:4312:270 min12:270 min12 Oct
Sydney15:59 → 13:4311:180 min11:1848 min12 Oct
Suva17:59 → 15:4311:290 min11:2948 min12 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

About Ahargaṇa