Ruling · Caitrī Pūrṇimā · 1990

Tuesday 10 April

Boundaryin Daqing, under the Rashtriya Panchang method. A threshold is only 0 min 35 s away. Say “contested”.

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 Monday 9 April

Qualifies with 48 of 48 minutes. Not taken.

madhyāhna begins 11:18  12:06 madhyāhna ends
10:3010:5411:1811:4212:0612:3012:54

48 of 48 minutes covered

Midday of Tuesday 10 April

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

madhyāhna begins 11:18  12:06 madhyāhna ends
Pūrṇimā ends 11:18:28
10:3010:5411:1811:4212:0612:3012:54

1 of 48 minutes covered, the first 1

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

How it was decided

  1. 01

    Aṅga

    Pūrṇimā runs from 09:24 on Mon 9 Apr to 11:18 on Tue 10 Apr.

    1990-04-09T01:24:13Z → 1990-04-10T03:18:29Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:18–12:06 on the 9th, 11:18–12:06 on the 10th.

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

  3. 03

    Rule

    Pūrṇimā must be present during madhyāhna. It covers 48 of 48 minutes on the 9th and 1 of 48 on the 10th.

    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 35 s < 300 s

  5. 05

    Ruling

    Caitrī Pūrṇimā, Daqing, 1990: Tuesday 10 April.

    confidence: boundary (margin)

Say it like this

In Daqing, Caitrī Pūrṇimā 1990 falls on Tuesday 10 April. Pūrṇimā runs from 09:24 on Mon 9 Apr to 11:18 on Tue 10 Apr and covers 1 of 48 minutes of madhyāhna that midday. It also reaches the previous midday for 48 minutes; by the rule the second midday is taken. It is 0 min 35 s from a threshold: treat the date as contested.

ahargana.org/daqing/festivals/1990/chaitri-purnima · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingTue 10 Apr
Ahargaṇa, classicalDisc centre, no refractionTue 10 Apr
compat-drikpanchangComparison profileTue 10 Apr
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/chaitri-purnima · ruleset 2026.3-draft

Month
Caitra, amānta
Pakṣa · aṅga
Śukla · Pūrṇimā
Kāla
Madhyāhna
Priority
Paraviddhā
Tie-break
Second day
Reference
CRC 1955, p. 102

“S 15 Caitri purnima (paraviddha), Hanumat jayanti, Oli ending (Jain).” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 102.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlacePūrṇimāMadhyāhna 9thCoveredMadhyāhna 10thCoveredRuled
Los Angeles18:24 → 20:1812:3148 min12:310 min9 Apr
Chicago20:24 → 22:1812:2948 min12:280 min9 Apr
Jersey City21:24 → 23:1812:3448 min12:340 min9 Apr
Port of Spain21:24 → 23:1811:4448 min11:430 min9 Apr
London02:24 → 04:1812:3948 min12:380 min9 Apr
Durban03:24 → 05:1811:3348 min11:330 min9 Apr
Dubai05:24 → 07:1811:5748 min11:560 min9 Apr
Delhi06:54 → 08:4811:5948 min11:590 min9 Apr
Kolkata06:54 → 08:4811:1448 min11:140 min9 Apr
Singapore09:24 → 11:1812:4248 min12:420 min9 Apr
Sydney11:24 → 13:1811:3348 min11:3248 min10 Apr
Suva13:24 → 15:1811:440 min11:4448 min10 Apr
Profile · tradition
pac-rp@2026.1 · smarta
Rule
chaitri-purnima@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s

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