Ruling · Rādhāṣṭamī · 1918

Friday 13 September

Boundaryin Shaoxing, under the Rashtriya Panchang method. A threshold is only 2 min 35 s away. Say “contested”.

Decide it for

ShaoxingDelhiKolkataSingaporeSydneyJersey City

30°00′ N 120°35′ E · Asia/Shanghai · GeoNames 1795855

The two middays

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

Midday of Friday 13 September

Taken. The only midday Aṣṭamī reaches.

madhyāhna begins 11:30  12:18 madhyāhna ends
10:4211:0611:3011:5412:1812:4213:06

48 of 48 minutes covered

Midday of Saturday 14 September

Aṣṭamī is absent from madhyāhna. Not taken.

madhyāhna begins 11:29  12:17 madhyāhna ends
Aṣṭamī ends 11:26:46
10:4111:0511:2911:5312:1712:4113:05

0 of 48 minutes covered

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

How it was decided

  1. 01

    Aṅga

    Aṣṭamī runs from 10:26 on Fri 13 Sep to 11:27 on Sat 14 Sep.

    1918-09-13T02:25:47Z → 1918-09-14T03:26:47Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:30–12:18 on the 13th, 11:29–12:17 on the 14th.

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

  3. 03

    Rule

    Aṣṭamī must be present during madhyāhna. It covers 48 of 48 minutes on the 13th and 0 of 48 on the 14th.

    Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 103

  4. 04

    Tie-break

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

    priority: unstated → only-day · margin 155 s < 300 s

  5. 05

    Ruling

    Rādhāṣṭamī, Shaoxing, 1918: Friday 13 September.

    confidence: boundary (margin)

Say it like this

In Shaoxing, Rādhāṣṭamī 1918 falls on Friday 13 September. Aṣṭamī runs from 10:26 on Fri 13 Sep to 11:27 on Sat 14 Sep and covers all of madhyāhna that midday. It is 2 min 35 s from a threshold: treat the date as contested.

ahargana.org/shaoxing/festivals/1918/radhashtami · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingFri 13 Sep
Ahargaṇa, classicalDisc centre, no refractionFri 13 Sep
compat-drikpanchangComparison profileFri 13 Sep
No institution has a recorded ruling for Shaoxing.

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

The rule, as data

/rules/radhashtami · ruleset 2026.3-draft

Month
Bhādrapada, amānta
Pakṣa · aṅga
Śukla · Aṣṭamī
Kāla
Madhyāhna
Priority
Unstated
Tie-break
Longer coverage, as a boundary
Reference
CRC 1955, p. 103

“S 8 Durvastami (purvaviddha — S 8 of saura Bhadra except Bengal), Mahalaksmi vratarambha, Radhastami (madhyahna vyapini)” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 103.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlaceAṣṭamīMadhyāhna 13thCoveredMadhyāhna 14thCoveredRuled
Los Angeles19:26 → 20:2712:2548 min12:240 min13 Sep
Chicago21:26 → 22:2712:2248 min12:220 min13 Sep
Jersey City22:26 → 23:2712:2848 min12:280 min13 Sep
Port of Spain22:26 → 23:2711:3848 min11:380 min13 Sep
London03:26 → 04:2712:3248 min12:320 min13 Sep
Durban04:26 → 05:2711:2848 min11:280 min13 Sep
Dubai06:07 → 07:0811:3248 min11:310 min13 Sep
Delhi07:56 → 08:5711:5348 min11:530 min13 Sep
Kolkata07:56 → 08:5711:0948 min11:080 min13 Sep
Singapore09:26 → 10:2711:3748 min11:360 min13 Sep
Sydney12:26 → 13:2711:280 min11:2748 min14 Sep
Suva14:26 → 15:2711:390 min11:3848 min14 Sep
Profile · tradition
pac-rp@2026.1 · smarta
Rule
radhashtami@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s

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